analysis of maruti 800

Durga Shankar [email protected] - 1 -

Introduction


Introduction: In the present days when technology has so improved that all the

product become compact and more effective. One of the best example is size of

computer become so small and more effective.

Automobile manufacturer and designers want to reduce the size and

weight of different parts of automobile components. Companies are striving to

shorten the design cycles and to cut engineering as well as prototype cost, so that they

can reduce the overall weight, analysis time and manufacturing cost of the car and

improve the performance of car. Thus customer satisfaction would be improved.

By conventional design and analysis process it is very difficult to

make an actual radiator and make changes for improving the efficiency of radiator

and reducing the size of radiator. But with the help of advance design softwares

(Commercial s/w) like Pro/Engineer, CATIA & ANSYS etc. It is become possible to

create an accurate model of any part of automobile.

For analyzing the complex cooling, air flow characteristics and

resulting thermal performance of the radiator and other heat generating components

in the engine compartment can be easily understand by utilize cost effective

numerical tools such as computational Fluid dynamics (which is a part of ANSYS).

The radiator of a Maruti 800 (MB308) car is studied

and modeled to determine the heat transfer rates, temperature profiles and overall

efficiency.

The actual radiator is measured and a model is made native in Pro/Engineer.

All the features of the row including the hollow water tubes and the fins are recreated to

ensure the most accurate model. The analysis is done with air, when traveling at different

speeds across the radiator.

ANSYS is used to calculate the air velocity distribution over the radiator.

The objective is to show how CFD can be used as a practical engineering tool to

complement and enhance the design process.

So, by using these advance commercial softwares environment we can

improve the effectiveness and overall performance of any part (radiator) of the car.


Need of Analysis: Automotive companies are trying to shorten design cycles and to cut engineering

as well as prototype costs. The condition demand a better understanding of the complex

cooling air flow characteristics and resulting thermal performance of the radiator and other

heat generating components in the engine compartment.

Here we use cost effective numerical tool COMPUTATIONAL FLUID DYNAMICS

(CFD) as a part of the systems engineering.

It is used as a practical engineering tool to complement and enhance the design process.

Computer simulation: Simulation is a broadly used and somewhat ill-defined term from the

engineering point of view. According to Webster’s international dictionary “To simulate”

means “To feign, to attain the essence without the reality”. However, the simplest meaning

of simulation is “imitation”. These dictionary meanings don’t bring out a clear picture of

the word “Simulation” for engineering applications. Therefore, a definition of the word

“Simulation” is more appropriate in this context. With some trepidation, the author defines

simulation as follows:

“Simulation is the process of designing of a model of a real system and conducting

experiments with it, for the purpose of understanding the behavior of the system.”

Computer simulation has gained greater importance these days because of the

availability of fast digital computers. It can be defined as follows:

Computer simulation is the process of formulating a model of physical system

representing actual processes and analyzing the same. Usually, the model is a mathematical

one representing the actual processes through set of algebraic, differential or integral

equations and the analysis is made using a computer.

In modern research, computer simulation has become a powerful tool that saves time and is

also economical when compare to experimental study. A propose theory can be analyzed

quickly using a computer and the cost of setting up an experimental apparatus can be

postponed until the optimization is achieved. However, it may be noted that simulation is

only a step prior to experimentation and the results obtained from simulation studies must

be validated with experimental results to establish the reliability. Once validated, computer


simulation can provide a deep insight into the performance characteristics of the system.

This statement is particularly true for the case of radiator studies.

A computer simulation or a computer model is a computer program that attempts

to simulate an theoretical model of a particular system. Computer simulations have become

a useful part of modeling many process of engineering new technology .

Types of computer simulation: Computer models can be classified according to several criteria including:

• Stochastic or deterministic (and as a special case of deterministic, chaotic)

• Continuous or discrete (and as an important special case of discrete, discrete event

or DE models).

• Local or distributed.

For example: • Stochastic models use random number generators to model the chance or random

events; they are also called Monte Carlo simulations.

• A discrete event simulation (DE) manages events in time. Most computer, logic-test

and fault-tree simulations are of this type. In this type of simulation, the simulator

maintains a queue of events sorted by the simulated time they should occur. The

simulator reads the queue and triggers new events as each event is processed. It is

not important to execute the simulation in real time. It's often more important to be

able to access the data produced by the simulation, to discover logic defects in the

design, or the sequence of events.

• A continuous simulation uses differential equations (either partial or ordinary),

implemented numerically. Periodically, the simulation program solves all the

equations, and uses the numbers to change the state and output of the simulation.

Most flight and racing-car simulations are of this type. This may also be used to

simulate electrical circuits. Originally, these kinds of simulations were actually

implemented on analog computers, where the differential equations could be

represented directly by various electrical components such as op-amps. By the late

1980s, however, most "analog" simulations were run on conventional digital

computers that emulate the behavior of an analog computer.

• A special type of discrete simulation which does not rely on a model with an

underlying equation, but can nonetheless be represented formally, is agent-based

simulation. In agent-based simulation, the individual entities (such as molecules,


cells, trees or consumers) in the model are represented directly (rather than by their

density or concentration) and possess an internal state and set of behaviors or rules

which determine how the agent's state is updated from one time-step to the next.

• Distributed models run on a network of interconnected computers, possibly through

the Internet. Simulations dispersed across multiple host computers like this are

often referred to as "distributed simulations". There are several military standards

for distributed simulation, including Aggregate Level Simulation Protocol (ALSP),

Distributed Interactive Simulation (DIS) and the High Level Architecture (HLA).

Computer simulation in Engineering:

Generic examples of types of computer simulations in engineering, which are

derived from an underlying mathematical description:

• a numerical simulation of differential equations which cannot be solved

analytically, theories which involve continuous systems such as phenomena in

cosmology, fluid dynamics (e.g. climate models, roadway noise models, roadway

air dispersion models) fall into this category.

• a stochastic simulation, typically used for discrete systems where events occur

probabilistically, and which cannot be described directly with differential equations

(this is a discrete simulation in the above sense). Phenomena in this category

include genetic drift, biochemical or gene regulatory networks with small numbers

of molecules. (see also: Monte Carlo method).

Advantage of computer simulation in Radiator Analysis: • It serves as a tool for a better understanding of the variables involved and

their effect on radiator performance.

• It reduces considerably the time-consuming tests by narrowing down the

variables that must be studied.

• It helps in optimizing the radiator design for a particular application,

reducing cost and time.


Objective of the Project:

• Predict temperature distribution over the radiator tubes and fins.

• Determine the heat transfer rate from the radiator.

• Predict velocity distribution over the radiator tube.

• Determine the efficiency of fins.

• Determine the effectiveness of radiator.

• Graphical outputs from the simulation included the velocity vectors and the

contour plots detailing the flow characteristics around the front end of the

car and over the radiator.

• Developing the program in C++ language.


Principle of the cooling system

&

Heat Transfer

Principle of the cooling system:

The purpose of the cooling system is to do three things:

• To maintain highest and most operating temperature with in

• To remove excess heat from the engine.

• To bring the engine up to operating temperature as quickly a

If the engine is not at the highest operating temperature,

efficiently, fuel mileage will decrease and wear on the engine components w

With in the gasoline or diesel engine, energy from the fuel is conver

moving the vehicle .Not all of the energy however is converted to pow

Figure 2.

• 25% and to push the vehicle (output)

• 9% radiant loss

• 33% exhaust loss

• Remaining 33% must be removed by cooling system

Most of the energy approximately 70% in the gasoline engine is converted

Durga Shankar er_dsgupta@rediffmail. - 8 -

Cooling system

Figure 1

the engine.

s possible.

it will not run

ill increase.

ted to power for

er Referring to

into heat.

com

. .

If the engine temperature is too high, various problems will occur, these include:

• Overheating of lubricating oil-this will result in the lubricating oil

breaking down.

• Over heating of the parts-This may causes loss of strength of the metal.

• Excessive stress between engine parts- This may cause increase in

friction, which may cause excessive wear.

If the engine temperature is too low, various problems will occurs, this includes:

• Poor fuel mileage-The combustion process will be less efficient.

• Increase in carbon built up-As the fuel enters the engine, it will condense

and cause excessive built up on the intake valves.

• Loss of the power if the combustion process is less efficient, the power

output will be reduced.

• Fuel not being burned completely, this will cause fuel to dilute the oil and

cause excessive engine wear.



Heat transfer: Heat transfer occurs when a temperature difference exists. As a result of

combustion, high temperatures are produced, inside the engine cylinder. Considerable heat

flow occurs from gases to the surrounding metal walls. However, the heat transfer on this

account is quite small. Hence, the cylinder wall must be adequately cooled to maintain safe

operating temperatures in order to maintain the quality of the lubricating oil.

Heat transfer from gases to the cylinder wall may occur predominantly by

convection and radiation whereas the heat transfer through the cylinder wall occurs only by

conduction. Heat is ultimately transferred to the cooling medium by all the three modes of

heat transfer. The temperature profiles across the cylinder barrel wall are shown in figure 3

for water-cooled engine. In this case, Tg, is mean gas temperature which may be as high as

8500C. This may not be confused with the peak temperature of the cycle which may be two

or three times this value. Largest temperature drop, however, occurs in the boundary layer

of the gas which lies adjacent to the cylinder wall. There is a corresponding boundary-layer

in the cooling medium on the outer side of

the cylinder. However, because of fins in the air-cooled engines the effect of external

boundary layer is reduced.

The conduction of heat through cylinder walls with corresponding

temperature gradients is illustrated in the figure 3. The gas film, being of low conductivity,

offers a relatively high resistance to the heat flow, whilst on the water jacket side there is

usually a layer of corrosion products, scale etc, which the poor conductors of heat. The

least resistance to the heat flow occurs through the metal cylinder wall, as shown by the

temperature gradient there. In actual practice because of the cyclic operation of engines,

there is a cyclic variation of the gas temperature with in the cylinder the effect of which is

to cause a decrease of heat to travel into the metal which gradually dies out and after warm

up period a steady flow condition prevails. It has been experimentally established that in

internal combustion engine the cyclic temperature variation die out fast before fluctuations

reach the outside surface of the cylinder. Maximum temperature of the cylinder walls, in a

properly designed engine, seldom exceeds 100C above the mean temperature.

Figure 3

The cooling system works on the principle of heat transfer.

Heat will always travel from a hotter to cooler object. Heat transfer is in three ways

1. Conduction

2. Convection

3. Radiation

Conduction is defined as transfer of heat between two solid object .for examples

referring to figure 4, heat must be transferred from valve stem to valve guide. Since both

objects are solid, heat is transferred from hotter stem valve to cooler valve guide by

conduction. Heat is also transferred from the valve guide to cylinder head by conduction.


Valve Guide Valve Stem

Figure 4

Heat is transferred by conduction from the valve guide. Both objects are solid.

Heat can be transferred by convection; convection is defined as the transfer of

heat by circulation of heated parts of a liquid gas. When the hot cylinder block transfers

heat to the coolant, it is done by convection. Convection also occurs when the hot radiator

parts transfers heat to the coolant air surrounding the radiator.

Radiation is another way that heat is transferred. Radiation is defined as

transfer of heat by converting heat energy to radiant energy. Any hot object will give off

radiation. The hotter the object, the greater the amount of radiant energy. When the engine

is hot ,some of the heat is converted to radiant(about 9%).The cooling system relies on

these principles to remove the excess heat within the engine.


Variation of gas temperature: There is an appreciable variation in the temperature of the gases inside the

engine cylinder during different processes of the cycle. Temperature inside the engine

cylinder is almost the lowest at the end of the suction stroke. During combustion there is a

rapid rise in temperature to peak value which again drops during the expansion. This

variation of the gas temperature is illustrated in figure 5 for various processes in the cycle.

Figure 5


Figure 6

com

Piston temperature distribution: The piston crown is exposed to very high combustion temperature.

Figure-7 gives typical values of temperature at different parts of a cast iron piston. It

may be noted that maximum temperature occurs at the centre of the crown and

decrease at the outer edge. The temperature is the lowest at the bottom of the skirt.

Poor design may result in the thermal overloading of the piston at the centre of crown.

The temperature difference between piston outer edge and centre of the crown is

responsible for the flow of heat to the ring belt through the path offered by metal

section of the crown. It is therefore, necessary to increase the thickness of the crown

from the centre to the outer edge in order to make a path of greater cross-section

available for increasing the heat quantity.

The length of the path should not be too long or the thickness of the crown cross-

section is too small for the heat to flow. This may even lead to cracking of the piston during

overload operation.


Figure 7

Cylinder temperature distribution: Whenever a moving gas comes in to contact with a wall, there exists a relatively

stagnant gas layer which act as a thermal insulator. The resistance of this layer to heat flow

is quite high. Heat transfer from the cylinder gases takes place through the gas layer and

through the cylinder walls to the cooling medium. A large temperature drop is produced in

the stagnant layer adjacent to the walls.

The peak cylinder gas temperature may be 2800K while the temperature

of the cylinder inner wall surface may be only 450K due to cooling. Heat is transferred

from the gases to the cylinder walls when the gas temperature is higher than the wall

temperature. The rate and direction of flow of heat varies depending upon the temperature

differential. If no cooling is provided there could be no heat flow, so that the whole

cylinder wall would soon reach an average temperature of the cylinder gases. By providing

adequate cooling, the cylinder wall temperature can be maintained at optimum level.

Figure 8


Figure 9



Theory of engine heat transfer:

In spite of its high temperature, the cylinder gas is poor radiator and almost

all the heat transfer to the cylinder walls from combustion space is by convection. In order

to understand the engine heat transfer, a simple analysis can be followed for the flow of

heat gases through the pipe.

For gases in pipes it can be shown by dimensional analysis and also through

experiments that

hL/k = Z×( ρCL/µ)n×(Cpµ/k)m (1.0)

Where

h= coefficient of heat transfer

L= any characteristic length

k= thermal conductivity of the gases

Z= constant

ρ= mass density of gases

C= velocity of gases

µ=viscosity of gas

n, m=exponents

The term (ρCL/µ) can be recognized as Reynolds no. for cylinder gases. The term

(Cpµ/k)is called the Prandtl number and is nearly constant for gases. Therefore, Prandtl

number can be absorbed in the constant Z in equation 1.0 so that-

hL/k = Z×( ρCL/µ)n (1.1)

Since prandtl number is constant, k α Cpµ and substituting Cpµ for k in equation 1.0.

hL/Cpµ = Z×(ρCL/µ)n (1.2)


h=Z×Cp×(ρC)n×(L/ µ)n-1 (1.3)

The rate of heat transfer can be written as-

q=h×A×∆T

Where ∆T is the temperature difference between the gas and wall.

Substituting the value of h from equation (1.3) we get

q= Z×Cp×(ρC)n×(L/ µ)n-1× A×∆T (1.4)

In the above expression, A is the area of the heat transfer which is proportional to

L2 and S is the mean piston speed which is proportional to gas velocity C. when the

average gas temperature is considered Cp and µ can be assumed to have constant values,

then

q= Z× (ρS)n×Ln+1×∆T (1.5)

Piston speed is proportional to the product of L and N where N is the rpm of the engine.

Volumetric efficiency, ηv is proportional to the density of charge ρ, then

q= Z× (ηvN)n×L2n+1×∆T (1.6)

The average temperature of the cooling medium, the fuel-air ratio of the mixture

and the compression ratio of the engine directly influence the value of ∆T.The density is

mainly affected by the intake pressure, compression ratio and the volumetric efficiency,ηv.

Those engines which have nearly equal value of ∆T, the heat transfer rate depends on the

product of ηvN and the size of the engine.

For engines when ∆T is assumed to be invariant-

q= Z× (ηvN)n×L2n+1 (1.7)

The value of Z and n are determined from the experiments on a particular type of

engine under various operating conditions. The constants so obtained can be used for

calculating heat transfer rate for other operating conditions of the same engine or for

geometrically similar engine.


Parameters Affecting Engine Heat Transfer: The engine heat transfer depends upon many parameters. Unless the effect

of these parameters is known, the design of a proper cooling system will be difficult. In this

section, the effect of various parameters on the engine heat transfer is briefly discussed.

1. Fuel-Air Ratio: A change in fuel-air ratio will change the temperature of the cylinder gases

and affect the flame speed. The maximum gas temperature will occur at an equivalence

ratio of about 1.12 that is at a fuel-air ratio about 0.075. At this fuel-air ratio ∆T will be a

maximum. However from experimental observations the maximum heat rejection is found

to occur for a mixture, slightly leaner than this value.

2. Compression Ratio: An increase in compression ratio cause only a slightly increase in gas

temperature near the top dead centre, but because of the greater expansion of the gases,

there will be a considerable reduction in gas temperature near bottom dead centre where a

large cylinder wall is exposed. The exhaust gas temperature will also be much lower

because of greater expansion so that the heat rejected during blow down will be less. In

general, as compression ratio increases there tend to be a marginal reduction in heat

rejection.

3. Spark Advance: A spark advance more than the optimum as well as less than the optimum

will result in increased heat rejection to the cooling system.

This is mainly due to the fact that spark timing other than MBT value

(Minimum spark advance for Best Torque) will reduce the power output and thereby more

heat is rejected.

4. Preignition And Knocking: Effect of preignition is the same as advancing the ignition timing. Large

spark advance might lead to erratic running and knocking. Though knocking cause large

change in local heat transfer conditions, the overall effect on heat transfer due to knocking

appears to be negligible. However no quantitive information is available regarding the

effect of preignition and knocking on engine heat transfer.


5. Engine Output: Engines which are designed for high mean effective pressure or high piston

speeds, heat rejection will be less. Less heat will be lost for the same indicated power in

large engines.

6. Cylinder Wall Temperature: The average cylinder gas temperature is much higher in comparison to the cylinder wall

temperature. Hence, any marginal change in cylinder gas temperature will have very little

effect on the temperature and thus on heat rejection.

A typical temperature distribution (figure 8) which would be found in an I.C.

engine operating at steady state, three of the hottest points are:

1. Around the spark plug.

2. The exhaust valve and port.

3. The face of the piston.

Not only are these places exposed to the high temperature gases, but they are

difficult places to cool.

Highest gas temperature during combustion occurs around the spark plug.

This creates a critical heat transfer problem area. The spark plug fastened through the

combustion chamber wall creates a disruption in the surrounding water jackets, causing a

local cooling problem. On air-cooled engines the spark plug disrupts the cooling fin

pattern, but the problem may not be as severe. The exhaust valve and port operate hot

because they located in the pseudo steady flow of hot exhaust gases and create a difficulty

in cooling similar to the one the spark plug creates. The valve mechanism and connecting

exhaust manifold make it very difficult to route coolant or allowed a finned surface to give

effective cooling.

The piston face is difficult to cool because it separated from the water

jackets or outer finned cooling surface.


Heat transfer in combustion chamber: Once the air-fuel mixture is in the cylinders of an engine, the three

primary modes of heat transfer (conduction, convection, radiation) all play an important

part for smooth steady state operation. In addition the temperature with in the cylinders is

affected by a phase change-evaporation of the remaining liquid fuel.

The air-fuel mixture entering the cylinder during the intake stroke may

be hotter or cooler than the cylinder wall, with the resulting heat transfer being possible in

either direction. During the compression stroke, the temperature of the gas increases, and

by the time combustion starts, there is already a convective heat transfer to the cylinder

walls. Some of this compressive heating is lessened by the evaporating cooling which

occurs when the remaining liquid fuel droplets vaporize.

During combustion peak gas temperature on the order of 3000K occur within

the cylinders, and effective heat transfer is needed to keep the cylinder walls from

overheating. Convection and conduction are the main heat transfers modes to remove

energy from the combustion chamber and keep the cylinder walls from melting.

The basic idea is that according to Foriour law for small ∆x,

q=-k (∆T/∆x)

Heat transfer through a cylinder wall. Heat transfer will be

Q= (Tg-Tc)/ [1/hgAg+ {ln (rc/rg)/ (2πkL)} +1/Achc] (1.8)

Where

Tg- gas temperature in the combustion chamber

Tc- coolant temperature

hg- convection heat transfer coefficient on the gas side.

hc- convection heat transfer coefficient on the coolant side.

Ag-inside area of cylinder

Ac-area of cooling jacket around the cylinder

rg –radius of piston

rc-radius of cooling jacket

k- Thermal conductivity of the cylinder wall.

Heat transfer through the combustion chamber cylinder wall of an I.C. engine.

The cylinder gas temperature Tg and convection heat transfer coefficient hg vary over large

ranges for each engine cycle, while the coolant temperature Tc and heat transfer coefficient


hc are fairly constant, as a result of this, heat conduction is cyclic for a small depth in to the

cylinder wall on the combustion chamber side.

Heat transfer in above equation (1.8) is cyclic.

Gas temperature Tg in the combustion chamber varies greatly over an engine

cycle, ranging from maximum values during combustion to minimum during intake. It can

even be less than wall temperature early in the intake stroke, momentarily reversing heat

transfer direction. Coolant temperature Tc is fairly constant, with any change occurring

over much longer cycle times.

The coolant is air for air-cooled engines and antifreeze solution for water

cooled engine. The convection heat transfer coefficient hg on the cylinder gas side of the

wall varies greatly during an engine cycle due to change in gas motion, turbulence, swirl,

velocity etc. this coefficient will also have large spatial variation with in the cylinder for

same reasons. The convection heat transfer coefficient on the coolant side of the wall will

be fairly constant, being dependent upon coolant velocity.

Thermal conductivity k of the cylinder wall is a function of wall temperature and

will be fairly constant.

Convection heat transfer on the inside surface of the cylinder is-

q= Q/A =hg (Tg-Tc) (1.9)

Wall temperature Tw should not exceed 1800C-2000C to assure thermal stability of the

lubricating oil and structural strength of the wall.

There are a number of ways to identifying a Reynolds number to use for comparing flow

characteristics and heat transfer in engines of different sizes, speed and geometrics.

Choosing the best characteristic length and velocity is sometimes difficult. One way of

defining a Reynolds no for engines which correlates data fairly well is

Re= ((ma+mf)D)/(Ap*µg) (1.10)

Where

ma=mass flow rate of air in to cylinder

mf= mass flow rate of fuel in to cylinder

D=bore

Ap=area of piston face

µg =dynamic viscosity of gas in the cylinder

A nusselt number for the inside of the combustion chamber can be defined using this

Reynolds number.

Nu=hgD/kg=C1(Re)C2 (1.11)


Where C1 and C2 = constant

Kg=thermal conductivity of cylinder gas

hg=average value of the convection heat transfer coefficient to be used in eqn(1.8).

Types of cooling system: Engine manufacturers today commonly used two types of cooling system.

• Air cooled system

• Liquid cooled system

Air-cooled engine: Several producers have designed engines that are air cooled. Certain foreign

manufacturers still use air cooled engines. Air cooled engines have fins or ribs over the

outer surfaces of the cylinder and cylinder heads. These fins are cast directly to the cylinder

and heads. The fins increase the surface area of the object which, in turn, increases the

amount of convection and radiation available for heat transfer. The heat produced by the

combustion transfers from the internal parts of the engine by conduction to outer fins. Here

the heat is dissipated to the passing air. In some cases, individual cylinders are used to

increase air circulation around the cylinder.

Air cooled engines require air circulation around the cylinder block and

heads. Some sort of fan is usually used to move the air across the engine. A shroud is also

used in some cases to direct or control the flow of air across the engine. Air cooled engine

usually do not have exact control over engine temperature, however they do not use a

radiator and water pump. This may reduce maintenance on the engine over along period of

time.

The basic principle involved in this method to have current of air flowing

continuously over a heated metal surface from where the heat is to be removed. The heat

dissipated depends upon following factors

• Surface area of metal into contact with air.

• Mass flow rate of air.

• Temperature difference between the heated surface and air.

• Conductivity of metal.

Thus for an effective cooling the surface area of the metal which in

contact with the air should be increased. This is done by using fins over the cylinder


barrels. These fins are either cast as an integral part of the cylinder or separate finned

barrels are inserted over the cylinder barrel. Sometimes, particularly in the case of aero

engine, the fins are machined from the forged cylinder blanks. To increase the contact area

still further, baffles are used sometimes.

Use of copper and steel alloy has also been made to improve heat transfer because of

their better thermal conductivity.

Advantages:

• Air cooled engines are lighter because of the absence of the radiator, the

cooling jackets and the coolant.

• They can be operated in extreme climates, where the water may freeze.

• In certain areas where there is scarcity of cooling water, the air cooled

engine has an advantage.

• Maintenance is easier because the problem of leakage is not there.

• Air cooled engine get warmed up earlier than the water cooled engine.

Disadvantages:

• It is not easy to maintain even cooling all around the cylinder, so that the

distortion of the engine takes place. This defect has been remedied sometimes

by using fins parallel to the cylinder axis. This also helpful where a no. of

cylinders in row are to be cooled.

However, this increases the overall engine length

• As the coefficient of the heat transfer for air is less than that for water, there is

less efficient cooling in this case and as a result the highest useful compression

ratio is lesser in the case of air cooled engines than in the water cooled ones.

• The fan used is very bulky and absorbs a considerable portion of the engine

power (about 5%) to drive it.

• Air cooled engines are more noisy, because of the absence of the cooling water

which acts as sound insulator.

• Some engine components may become inaccessible easily due to guiding

baffles and cooling, which makes the maintenance difficult.

• The cooling fins around the cylinder may vibrate under certain conditions due to

which noise level would be considerably enhanced.


Liquid-cooled engines: In a liquid cooled engine the heat from the cylinder is transferred to a liquid

flowing through jackets surrounding the cylinders. The liquid then pass through a radiator.

Air passing through the radiator removes the heat from liquid to the air. Liquid cooling

systems usually have better temperature control than air cooled engine. They are designed

to maintain a coolant temperature of

820C-980C. The engine runs best when its coolant is about 200 degrees Fahrenheit (93

degrees Celsius).

Liquid coolant flow: When the vehicle is started, the coolant pumps begin circulating the coolant. The

coolant goes through the cylinder block from the front to the rear. The coolant circulates

around the cylinders, and passes through the cylinder block.

The coolant then passes up into the cylinder head through the hole in the head

gasket. From there, it moves forward to the front of the cylinder head through internal

passages. These passages permit cooling of high heat areas like spark plug and exhaust

valve areas.

As the coolant leaves the cylinder head, it passes through a thermostat on the

way to the radiator. As long as the coolant temperature remains low, the thermostat stays

closed. Under these conditions the coolant flows through the by-pass tube and returns to the

pump for recirculation through the engine. As the coolant heats up, the thermostat

gradually opens to allow enough hot coolant to pass through the radiator. This will

maintain the engine’s highest operating temperature.

Figure 10

From the thermostat, the coolant flows to the internal passages in the

radiator. There are tubes in the core with small fins on them. The coolant is now being

cooled by the air passing through the radiator. From there it returns to the outlet of the

radiator and back to the pump. It then continues its circulation through the engine.



Maruti 800 (MB 308) coolant

characteristics


Maruti800 (MB308) coolant characteristics: Ethylene glycol (monoethylene glycol (MEG))

IUPAC name: Ethane-1, 2-diol

Ethylene glycol is an alcohol with two -OH groups (a diol), a chemical

compound widely used as an automotive antifreeze. In its pure form, it is an odorless,

colorless, syrupy liquid with a sweet taste. Ethylene glycol is toxic, and its accidental

ingestion should be considered a medical emergency.

Water is one of the most effective fluids for holding heat, but water freezes

at too high a temperature to be used in car engines. The fluid that most cars use is a mixture

of water and ethylene glycol (C2H6O2), also known as antifreeze. By adding ethylene

glycol to water, the boiling and freezing points are improved significantly.

The temperature of the coolant can sometimes reach 2500F to 2750F

(1210C to 1350C). Even with ethylene glycol added, these temperatures would boil the

coolant, so something additional must be done to raise its boiling point.

The cooling system uses pressure to further raise the boiling point of the coolant. Just as

the boiling temperature of water is higher in a pressure cooker, the boiling temperature of

coolant is higher if you pressurize the system.

Maruti 800 car radiator has a pressure limit not exceed than

0.9 kgf/cm2.

Antifreeze also contains additives to resist corrosion.

Water has been the most commonly used engine coolant. This is because it

has good ability to transfer heat and can be readily obtained. Water alone, however is not

suitable for today engines for a number of reasons . water has a freezing point 320F (00C).

Engines must operate in colder climates also water has a boiling point of 2120F (1000C).

Engine coolant temperature often exceeds this point. In addition, water can

be very corrosive and produce rust with in a coolant system.

To over come these problems, anti-freeze added to the coolant.

An ethylene glycol type anti-freeze coolant is used. This anti freeze includes suitable

corrosion inhibitors. The best percentage of anti-freeze to water to use is about 50% anti-

freeze mixed with 50% water.

Freezing point: Figure 11 shows what happens to the freezing point of a coolant when different

percentages of anti-freeze are used. For example, when 100% water is used, the freezing

point is 320F (00C). When 25% antifreeze and 75% water is used, the freezing point of the

coolant is about 100F. At 68% antifreeze, the freezing point of the coolant is about -920F.

As the amount of anti freeze percentage increases from this point, the freezing point goes

back towards 00F.

Boiling points:

The addition of anti freeze in the cooling system increases the boiling

point. The boiling point of a fluid is the temperature at which a liquid becomes vapor.

Any coolant that becomes a vapor has very poor conduction and convection

properties. Therefore, it is necessary to protect it from safety against engine cooling

system overheating failure.

Properties of antifreeze solutions:

Ethylene Glycol-Water Mixture:

%Ethylene

Glycol by

volume

Sp.Gravity

At 101 Kpa &

15 0C

Freezing

pt. at

101 kpa

0C 0F

Boiling pt.

at 101 kpa

0C 0F

0 1.000 0 32 100 212

10 1.014 -4 24 - -

20 1.029 -9 15 - -

30 1.043 -16 3 - -

40 1.056 -25 -14 - -

50 1.070 -38 -37 111 231

60 1.081 -53 -64 - -

100 1.119 -11 12 197 386

Table I


Thermal Properties:

Most heat is transferred in a cooling system by convection from hot metal

to a cooler liquid as in the engine block or from a hot liquid to cooler metal surfaces,

as in the radiator. The convection coefficient of liquids in a tube is a complicated

relationship between the thermal conductivity, viscosity of the liquid, and the tube

diameter, which determines the amount of turbulent flow. With almost 2.5 times

greater thermal conductivity than glycol-based coolants, water has amazingly

efficient heat transfer properties compared to virtually any other liquid cooling

medium. Mixtures of glycol and water have nearly proportional improvement due to

the addition of water.

Figure 11



Production: Ethylene glycol is produced from ethylene, via the intermediate ethylene oxide.

Ethylene oxide reacts with water to produce ethylene glycol according to the chemical

equation :

C2H4O + H2O → HOCH2CH2OH

This reaction can be catalyzed by either acids or bases, or can occur at neutral pH under

elevated temperatures. The highest yields of ethylene glycol occur at acidic or neutral pH,

with some of a large excess of water present. Under these conditions, ethylene glycol yields

of 90% can be achieved. The major byproducts are the ethylene glycol oligomers

diethylene glycol, triethylene glycol, and tetraethylene glycol.

Applications: The major use of ethylene glycol is as an engine coolant and antifreeze. Due to

its low freezing point, it has also been used as a deicing fluid for windshields and jet

engines.

Safety: The major danger from ethylene glycol is from its ingestion. Due to its sweet

taste, children and animals will sometimes consume large quantities of it if given access to

antifreeze. Symptoms of ethylene glycol poisoning follow a three-step progression doses as

small as 30 milliliters (2 tablespoons) can be lethal to adults

Corrosion: Corrosion in the cooling system can be vary damaging to the engine. Corrosion can be

produced in several ways. Direct attack means the water in the coolant is mixed with the

oxygen from air. This process can produce rust particles, which can damage water pump

seals and cause increased leakage. Electrochemical attack is a result of using different

metals in an engine.


Corrosion Protection: Modern automotive engines now use aluminium for heads, radiators, water

pump housings, and nearly all hose fittings. These engines require significantly greater

corrosion protection than cast iron counterparts of the past. Aluminium is an electro active

metal that requires an impenetrable corrosion inhibitor film to prevent rapid corrosion.

Acid neutralization capability is very important. Coolant left in a cooling system for several

years can become acidic from the oxidation of the glycol to acids. Also, keeping the glycol

concentration in the cooling system below 50% will help stability. Engine Coolant provides

excellent protection from cavitation erosion in the water pump and cylinder head.

Localized boiling in the cylinder head forms vapour bubbles, which collapse when they

come in contact with cooler liquids. This collapse creates tremendous shock waves, which

removes the inhibitor film from the aluminium surface and can cause catastrophic erosion

of the aluminium if the inhibitor does not reform the film quickly. Another problem created

by cavitation erosion is the deposition of the removed aluminium as a salt with poor heat

transfer properties in the lower temperature radiator tubes. Engine Coolant prevents this

corrosion through effective film formation and smaller vapour bubble formation which has

a less violent collapse. Foam control is equally important since entrained air will cause

cavitation erosion due to the collapse of foam bubble. Engine Coolant provides excellent

control of foam with water alone and with glycol solutions.


Parts of Liquid Cooling System

Parts of Liquid Cooling System:

• Thermostat

• Radiator

• Pressure Cap

• Hose pipes

• Fan

• Belt Drive

• Water Pump

Figure 12

1. Cylinder Block

2. Cylinder Head

3. Bypass

4. Radiator Pressure cap

5. Radiator

6. Coolant Pump

7. Fan

8. Fan Blade

9. Thermostat



Thermostats:

Function:

The thermostat is one of the most important part of the cooling system. It is

designed to sense the temperature of the coolant. If the temperature of the coolant remains

cold, the thermostat will be closed. The coolant then goes to the by-pass tube. This allows a

small amount of the coolant to pass in to the radiator to be cooled. The remaining coolant

flows through the by-pass tube. This coolant is recirculated without being cooled. If the

engine is under heavier load, more cooling will be necessary. If the temperature of the

coolant increases to opening temperature, the thermostat will open slightly. As the

temperature of the coolant increases further, the thermostat opens more. This allows more

coolant to reduce its temperature through the radiator. When the engine is under full load,

the thermostat will be fully open .the maximum amount of the coolant will be sent to the

radiator for cooling and a small amount of coolant will continue to flow through the by-

pass tube.

Thermostat operates on a very simple principle. A wax pellet material with in

the thermostat expands and causes the mechanical motion which opens the thermostat. This

allows coolant to pass through to the radiator. It should be noted that the thermostat is

opened only partially when the temperature reaches its opening point. As the coolant

temperature increases, the thermostat opens further. Eventually, the coolant is hot enough

to cause the thermostat to open fully to get maximum cooling.

Thermostats are designed to open at different temperatures. Maruti 800

thermostat operating temperatures are 820C and 980C.

Most thermostats in use are solid expansion “pill” type, basically a temperature

sensitive valve.

The thermostat is generally located between the front of the engine and top

(inlet) hose of the radiator. The thermostat is commonly contained a metal housing

connected to the hose.

Wax Palle

Exploded View of Thermostat Assembly

When we start a car the cooling system begins working

engine is cold, fast warm up-is critical, slow warm-up causes moisture

Durga Shankar er_dsgupta@rediffm - 36 -

Figure 13

t Thermostat

Figure 14

instantly. Since the

condensation in the

ail.com

combustion chamber and ultimately affect engine life time. To assist engine warm-up, the

thermostat shut off the flow of coolant.

Every engine has an optimum working temperature 160F to 180F to 195F,185F

to 228F, once the temperature sensitive valve reaches the correct range, the aperture open

and allow normal flow of the coolant.

The prime function of the thermostat is to promote fast warm-up and in doing so

avoid overcooling. Once an engine is at working temperature, the thermostat remains open

and regulate the temperature of the coolant. Avoiding excessive overheating is the

responsibility of other parts of the cooling system.

Durga Shankar er_dsgupta@rediffma - 37 -

Figure 15

il.com

Thermostat coolant by-pass: The thermostat coolant bypass is an important bypass that permits coolant to

reach the “hot” part of the engine during the warm up period. It allows coolant in the water

jacket- a special passage located next to the combustion chamber- to be circulated where it

is instantly needed. The thermostat remains closed so the only coolant moving is that in the

water jacket.

The bypass allows the coolant to circulate and pickup the heat created by

combustion (before the engine overheats) but does not interfere with the thermostat

preventing total circulation of the coolant. Once the optimum working temperature is

reached, the work of the bypass is done. The thermostat opens permitting full flow of the

coolant.


Figure 16


Thermostat Model:

The thermostat begins to open when the coolant temperature warms up

to a certain level. The thermostat continues to open more up to the point that it is

mechanically restricted. The engine coolant flow rate is dependent on the cross

sectional area of the thermostat. This opening area can be simplified to a linear

relationship of temperature from the thermostat opening coolant temperature to that

which causes the opening of thermostat to be at its maximum.

For, Teng<Tstat_min , Athermostat =0

For, Teng>Tstat_max, Athermostat =1

For, Tstat_min ≤Teng≤Tstat_ max,

Athermostat= (Teng−Tstat_min)/ (Tstat_ max −Tstat_ min)

Where; Athermostat =Thermostat opening area coefficient

Teng=Engine Coolant Model Temperature

Tstat_min = is the engine coolant temperature causing the thermostat begins to open and

Tstat_max = is the engine coolant temperature for maximum lift of the thermostat.


Radiator

(The Heart of Cooling)


Radiator: The Heart of Cooling:

Introduction: A radiator is a heat exchanger that removes heat from coolant passing

through it, thereby maintaining the engine temperature. This is done by heat transfer from

hot coolant coming from engine cooling jacket, flowing into the tubes via the Inlet tank.

Heat rejected from coolant to the tube is transferred to the ram air (ambient) flowing over

the fins.

The radiator is the most important element of the cooling system and has the

critical function of reducing temperature of the passing coolant. The “cooled” coolant

continues recirculating throughout the engine, removing heat waste. The coolant carrying

the heat waste from the engine moves into the radiator core via the inlet hose.

• Radiator Is a device which provides exchange of heat between two fluids are at

different temperatures.

• The function of the radiator is to transfer heat from the hot water flowing

through the radiator tubes to the air flowing through the closely spaced thin

plates outside attached to the tubes.

• A radiator consists of an upper tank, core & the lower (Collector) tank. Hot

coolant from the engine enters the radiator at the top & is cooled by the cross

flow of the air , while flowing down the radiator .The coolant collects in the

collector tank from where it is pumped to the engine for cooling.

• Radiator is recuperator heat exchanger, in this case the fluids exchanging heat

are on either side of dividing walls (in the form of pipes or tubes). These heat

exchanger are used when two fluids cannot allow to mix i.e. the mixing is

undesirable.

Coolant moves through the interior of Al tubes th

of Al fins at many points.

Heat, since it will always more to a cooler place-mo

the Al tubes, to the fines ,and then to the outside air.

The fins are designed to create a pause in air flow around

greater heat dissipation. The heat movement from metal to air occur

where the tubing and fines meet the exact points of heat dissi

radiation, the cooler the coolant and the cooler the engine.

The coolant enters into the “hot” or inlet tank of the r

the tubing to the “cool” or outlet tank is recirculated.

During normal operation, between 7570 and 26500 litr

through the radiator per driving hour.

Since overheating causes an engine damage, the radiator must work

from the coolant into the air so that the cooled coolant can recirculat

There is an inlet and outlet tank bonded to header pla

and fines together on the inlet tank is a filler neck.

The purpose of the radiator is to allow fresh air to reduce the tem

.This is done by flowing the coolant through tubes, as the coolant p

air is forced around the tubes. This causes a transfer of heat from

cooler air.

Durga Shankar er_dsgupta@red - 42 -

Figure 17

at are bounded to rows

ves from the coolant to

the tubes and to asset in

s primarily at the points

pation. The cooler the

adiator, moves through

es of coolant will move

quickly to transfer heat

ed through the engine.

tes that hold the tubing

perature of the coolant

asses through the tubes;

the hot coolant to the

iffmail.com

This process is called heat exchange in this cease, heat is exchanged from the

coolant, to air, this is called a liquid to air heat exchanger, note that the coolant flows

through the tubes and air flows through the air fines.

Radiator Construction:

Radiators are classified by the direction in which the tubing is assembled in the

core; two types of radiators are commonly used in the automobile.

• Down flow radiator.

• Cross-flow radiator.

Direction of Coolant flow

Figure 18 Cross Flow Radiator

Down Flow Radiator

In the down flow radiator, coolant flows form the top of the radiator to the

bottom .In the cross-flow radiator, the coolant flows from one side to the radiator to the

other side.

Maruti 800 used down flow radiator .Some automobile vehicle also and cross flow

radiator because newer vehicles are lowers in front; the cross flow radiator has been used

on most vehicles manufactured after 1970.



Classification of Maruti Radiators According To Manufacturing Processes:

There are two types of Radiators manufacturing Technologies used at CSIL (Climate

Systems India Limited):-

Type 1: MAAR (Mechanically Assembled Aluminium Radiator)

This technology involves joining of Tubes, fins, header, side support all

together using mechanical operation in which a hydraulic press is used to expand the tubes

over the header, there by providing a locking, this mechanical locking is further ensured by

providing epoxy resin cx which form’s a firm joint between the header and tubes.

It includes of:

• Round tubes

• Flat Contoured fins

• Sealing/joint obtained by mechanical interference, epoxy and rubber

gaskets.

MAAR Type Radiators includes:-

• Maruti 800

• YE2 ( Zen )

• OMNI

• GYPSY 1L & GYPSY 1.3L

• 3BOX ( Esteem )


Type 2: CABR (Controlled Atmosphere Brazed Radiator)

This technology involves joining of Tubes, fins, header, side support all

together using brazing operation in which a brazing material is sprayed over the radiator

and then it is heated at controlled temperature so that the brazing material melts and results

in brazed joints.

It includes of:-

• Elliptical tubes

• Corrugated fins

• Sealing/joint obtained by brazing and rubber gasket.

CABR Type Radiators includes:

• Model B ( Wagon R )

• Model A ( Alto )

• Model C ( Versa )

• Model K ( under development )

• Corsa ( under development )


Maruti 800(MB308) Radiator Parts

MAAR (Mechanically Assembled Aluminium Radiator):

Maruti 800(MB308) Radiator Parts:

Radiator are made of several parts

1. Core

2. Tanks

3. Side Support

4. Gasket

5. Pressure Cap

6. Drain Cock Assembly

Core: A Heater Core is a Heat Exchanger that removes heat from coolant passing

through it, thereby maintaining the engine temperature. This is done by Heat transfer from

hot coolant coming from the engine cooling jacket, flowing into the tubes via the Inlet tank.

Heat rejected from coolant to the tube is transferred to the ram air (ambient) flowing over

the fins.

Figure 19



Al tubes Al fins

Radiator Core

Figure 20

Parts of Core: Tubes, fins, header all together using mechanical operation in which a

hydraulic press is used to expand the tubes over the header, there by providing a locking,

this mechanical locking is further ensured by providing epoxy resin cx which form’s a firm

joint between the header and tubes.

• Header

• Tubes

• Fins

• Turbulatoes

Header: Function: There are two headers per radiator; headers are perforated plates through which

each tube protrudes. Header hold the matrix of the fin and the tube together ultimately

provide a mechanical mean to attach the tanks to the aluminium core.

Design: A header should be strong enough to withstand the operation and burst pressure.

Material of Header: Aluminium

Thickness of sheet: 1.0 mm


Aluminium Header

Figure 21

il.com

Round Tubes: Function: Carry coolant, hot from the engine, cold back to the engine. The heat exchange

is done through the tube wall, transferred to the fin and removed by the air passing through

the radiator.

Al Round Tube

Dimensions of tube:

Internal Diameter: 6 mm

External Diameter: 6.82 mm

Thickness of tube: 0.41 mm

Length of Tube: 340 mm

Material of the tube: Aluminium

Total No tubes used: 49(25 in one column & 24 in sec

Inner surface area: 6408.73 mm2

Outer Surface Area: 7284.73 mm2

Durga Shankar er_d - 50 -

Figure 22

ond column)

[email protected]

Fins: Function: The Fin or spacer is Flat strip of aluminium between each tube. It is the mean to

transfer heat from the tubes containing the coolant, to the air passing through the radiator.

The louvers are the angular cuts on the fin surface that insure some turbulence to the air as

it goes through, in order to increase the heat picked up by the air & therefore increase the

heat rejected by the radiator. The louvers must be as big as possible to maximize the

radiator efficiency but the airside pressure should be kept in mind, because it increases with

increase in louver angle & can affect the radiator efficiency.

Aluminium foil fin

Material of fins: Al foil Thickness: 0.21 mm Total no of fins used: 227 Length of fin: 350 mm Width: 28 mm Pitch: 14 mm Transverse pitch: 12.82 mm Staggered offset: 7 mm Single Fin Surface Area: 6873.51 mm2


Figure 23 Turbulators: Function:

1. To enhancing the turbulence in flow.

2. Increasing the surface area inside the tube.

Material: Aluminium Pitch: 2.8 mm Coil Dia.:5.25 mm Wire Dia.: 0.71 mm Pitch: 2.8 mm

Turbulator

Durga Shankar er_ds - 52 -

Figure 24

[email protected]

Tube –Turbulator Assembly


Figure 25
Figure 26

Tanks: Function: A radiator tank besides containing coolant is an important structural

member. It not only supports and connect a radiator core to the vehicle, but it also supports

the fan , motor and shroud assembly (engine side),condenser and possibly transmission oil

cooler , as well as sometimes a power steering , and hydraulic fan coolers as even as inter

coolers. Each radiator has two tanks: Inlet Tank receiving hot coolant from engine, and an

Outlet tank directing cooled coolant back to the engine.

Design: All the tanks are designed as per the customer requirements with the help of 3D

modeling software packages (Pro/Engineer etc.). Later on the mold flow analysis is done

before finalizing the mold design.

Material: Nylon 6/6+30% GF (Coolant Resistance)

Process: High Precision, High safety Injection Moulding.

Durga Shankar er_dsgup - 54 -

Figure 27

[email protected]

Upper Tank

Figure 28

Lower Tank


Side Support: Function: There are two side supports per radiator. They run parallel to the tubes and get

crimped, then brazed to the headers. Side Supports complete the frame that holds together

the fin tube matrix, especially during the manufacturing process. It also protects the first &

last fin of the radiator during handling before the radiator gets installed into a car. Side

support in CAB radiator act as a fin shield & does not bear any structural load.

Design: Side supports are on the shape of U channel.

Gasket: Function: There are two gaskets per radiator. A radiator gasket helps in maintaining a leak

proof joint between tank and header.

Rubber Gasket

Durga Shankar er_d - 56 -

Figure 29

[email protected]

Pressure Cap: Function:

Pressure capes are placed on the radiator to do several things;

They are designed to:

• Increase the pressure on the cooling system

• Reduce cavitations

• Protect the radiator hoses

• Prevent or reduce surging.

It is very important to maintain a constant pressure on the cooing system .The

pressure should be near 15 pounds/inch2 (103 kpa).

In the case of Maruti 800 Pressure should not exceed

0.90 kgf/cm2.

Pressure caps are placed on the radiator to maintain the correct pressure on the cooling

system. Pressure on the cooling system changes the boiling point .As pressure is increased,

the boiling point of the coolant also increases. This is shown in figure30. The bottom axis

shows pressure,

The vertical axis shows the boiling point .Different solution of antifreeze are also shown

.For example ,using water ,the boiling point at o psig(pressure per inch2 ,on a gauge ) is 212 0F (100 0C).


Figure 30

If the pressure is increased to 15 psig (103.42 kpa),the boiling point increases to about

2500F(121.110C). Figure31 shows how pressures cap maintain the constant pressure. As

the coolant increases in temperature, it begins to expand. As it expands, the coolant cannot

escape. The spring holds a rubber washer against the filler neck.


As the Pressure inccooling system, theeventually be liftedaction releases any0.9 kgf/cm2.

To Recovery Bottle


Figure 31

reases on the large spring off its seat. This pressure over
Figure 32
com

This keeps the fluid in the cooling system and increases the pressure. When the

pressure reaches .9kgf/cm2, the rubber seal is lifted off the filler neck against spring

pressure .The coolant then passes through the pressure cap to a tube that is connected to a

recovery bottle .This type of is called a closed system.

An open system allows the coolant to pass through the pressure cap directly to the

road surface.

The pressure cap also protects the hoses from expanding and collapsing. When

the engine is shut down, the coolant starts to cool. As it cools, the coolant shrinks.

Eventually, a vacuum is created in the cooling system .This means that the pressure outside

the radiator is greater than the pressure inside the radiator. This causes the hoses to

collapse. Continued expanding and collapsing of the hoses causes them to crack and

eventually leak. The pressure cap has a vacuum valve which allows atmospheric pressure

to seep into the cooling system where there is slight vacuum.

From Recovery Bottle

When the cooling system cools down, vacuum is produced in the system

spring is opened and the system equalizes the pressure.

During operation, a small spring holds the vacuum valve closed

a vacuum inside the cooling system, the vacuum valve is pulled down a

vacuum is then reduced with in the cooling system see figure-.

Increasing the pressure also reduces cavitations, cavitatio

earlier as small vacuum bubbles produced by the water pump action. Inc

reduced this action. Pressure on the cooling system also reduces surging. Su


Figure 33

. The vacuum

. When there is

nd opened. The

ns was defined

reased pressure

rging is defined

com

as sudden rush of water from the water pump. This could be caused by rapidly increasing

the rpm of the engine. Surging can produce air bubbles and agitation of the coolant.

Pressure on the cooling system tends to reduce this action.

Maruti 800 Pressure Cap


Figure 34

com

Vacuum spring Pressure Spring


Exploded view of pressure cap assembly

Drain Cock Assembly: Function: Drain Cock assembly constitutes a drain cock stem with threads on it & a

O-ring. It is usually placed in the Outer tank & acts as a point for draining of coolant

servicing of radiator.

Outer Ta

Drain Cock

Figure 35

rubber

during

nk

Figure 36


Radiator Assembly

Radiator Assembly:


Figure 37

com

Exploded view of Radiator Assembly

Figu


Figure 38

re 39

com


Hoses: The Connectors Hoses, made either of an elastremeric, flexible compound or a molded

rubber; are the connectors between the engine and the radiator and are the passages for

coolant. The bottom or outlet hose is on the outlet tank of the radiator. “Cooled” coolant

moves through this connector from the outlet tank of the radiator, through the water pump,

and into the engine. The top or inlet hose is on the inlet tank of the radiator. Through it hot

coolant returns from the engine for its recycling.

The outlet hose often has a spiral wire reinforcement that helps prevent

hose collapse due to excessive suction. The wire reinforcement can rust, causing rust

particle to enter the engine passage. Since the problem is not visible from the outside, the

inlet hose should be checked regularly. The one and only purpose of the hose is to provide

a constant, uninterrupted flow of coolant. Either spring-screw clamps or wire clamps are

used on hose ends.

Fans and Shrouds: Air flow Boosters Air, even in a liquid-based cooling system, is an important factor in

dissipating heat. Radiators designed with maximum air flow, are the prime vessels for

dissipating heat in the coolant to the outside air.

The fan, sitting directly behind the radiator, is simply a booster pulling cooler

outside air through the radiator core to assist heat throw-off.

There are various types of fans; thermostatic, centrifugal, fluid coupling, flexible

blade. Most are fixed, rigid blades attached directly to the water pump pulley (direct drive)

by cap screw or stud and nuts.

The rotation speed of the fan is determined by engine speed. In stop-and-go traffic,

or slow driving, insufficient air for cooling is pulled through the radiator core (especially in

large, high compression engine), and overheating can occur. Usually, when a car reaches a

certain speed, natural air flow helps cool but does not eliminates the need for a fan.

In case of Maruti 800, the fan operated through the electric motor controlled by the

thermostat switch, thermostat acts as a feedback device in the system.

Fan can also be variable pitch types using flexible blades that flatten out at high

speeds and spin freely without using more horse power from the engine.

With variable pitch fan, two types of fan clutches are used. Centrifugal fan

clutches will automatically increase or decrease fan rotation depending on engine speed.

Once adequate speed is reached, the centrifugal fan clutch will disengage the fan. Another

fan clutch is thermostatically controlled by engine and ambient air temperature. Once the

preset temperature is reached, the thermo viscous drive clutch disengages the fan.

The number and size of the blades differ according to vehicle requirements.

About the only problem that can occur is that one or all the blades becomes bent

or broken, the only recourse is replacement.

Depending on the vehicle, shrouds are installed to direct incoming air to the fan area.

These maintain spoilers act to funnel the air through the radiator.

From Maruti 800 service Manual: Fan starts at 980C and runs until temperature decreases t0 920c. When temperature

comes below 920C, the fan automatically turns off.

Fan temperature limits: 920C to 980C

Temperature sensor: Bourdan tube type and Electrically operated type.

Fan Drive: By Electrical Motor

Fan Controller: Thermostat switch

No. of Blades: 4

Radiator fan & shrouds


Figure 40

com


Material of fan: PA66 + 30% PF + GF

Process: Precision Injection Moulding

Material of shrouds: PA66 + 30% GF + MG

Process: Precision Injection Moulding

Drive belt: the power connectors The drive belts, or belts, turns the fan and the water pump for the cooling

system as well as for the generator, air conditioner compressor, and power steering pump.

Depending on the vehicle and accessory options, there may be from one to four belts.

All the belts are driven by a pulley attached directly to the crank shaft. The

faster the engine turns, the faster the belt and accessory rotate.

Incorrect belt tension invariably results in either overheating or premature

component failure. Insufficient or too little tension on the belt causes inadequate action.

The water pump does not rotate at the proper speed and the coolant circulates too slowly.

Overheating is the result on the other hand, too much tension on the water pump belt causes

excessive wear, and the water pump fails prematurely.

Water pump: The heartbeat

The water pump, usually made of die cast aluminium or cast iron, circulate

coolant into and through the cylinder block via the water jackets and through the thermostat

and by-pass. The coolant that carries engine heat passes through the radiator, transferring

this heat to the tubes and fins and then out to the out side air.

When fuel is ignited and combustion starts, temperatures in the cylinder

can reach 28000F plus, that is enough heat to melt an engine block and all its internal parts,

around this part of the engine- the combustion chamber- is a water jacket that surrounds the

block, head and intake manifold, and allows the coolant to these and other “hot” spots.

Should it be impossible to transfer this heat, the resultant overheating will be the woe of the

car owner. Seized pistons and bearings, burned values, and scored cylinders are the most

common physical damages incurred from overheating.

If the cooling system as faulty, or not in good working condition, the heat is

throws off will cause the engine metal to expand and contract beyond the tolerance levels

specified by the manufacturers. This expansion and contraction may cause gaps to form,

which in turn, cause oil leaks and destroy head gaskets.

A blown head gasket causes further problems by allowing exhaust gases to enter

the water jackets creating excess pressure in the cooling system and allowing heat from the

from the combustion chamber to more directly to the radiator. It also allows the air to enter

the block, eventually causing rust and block deterioration. A cracked head or cylinder block

creates similar problems.


Figure 41

il.

Figure 42

com


Analysis & Simulation

Analysis

ANALYSIS OF MARUTI 800 RADIATOR (MB308): Nomenclature:

Du

R

(L)

rga Shankar [email protected] - 71 -

R



• Radiator is a type of compact heat exchanger. • Surface area density >= 700 m2/m3. • Radiator is a recuperator type heat exchanger. • Maruti 800 model is single pass cross flow type radiator. • Extended surface heat exchanger. • Single phase conversion on both sides-Two fluids used. • No phase change occurs in any of fluids in the exchanger; it is sometimes referred to as a sensible heat exchanger. PARAMETERS: Coolant inlet Temperature (800C-1050C) =920C (From 2005 Maruti Suzaki Service Data Manual.) Coolant outlet Temperatures=? Air inlet Temperature(200C-400C)=270C. Air outlet Temperature=? Blend of Water+Ehylene Glycol (50/50). DIMENSIONS OF TUBE: Internal Diameter: 6 mm External Diameter: 6.82 mm Thickness of tube: 0.41 mm Length of Tube: 340 mm Material of the tube: Aluminium Total No tubes used: 49(25 in one column & 24 in second column) Inner surface area: 6408.73 mm2

Outer Surface Area: 7284.73 mm2

Figure 43

DIMENSIONS OF TURBULATOR: Material: Aluminium. Pitch: 2.8 mm Coil Dia.: 5.25 mm Wire Dia.: 0.71 mm Pitch: 2.8 mm Dhc: 5.29 mm DIMENSIONS OF FIN: Material of fins: Al foil Thickness: 0.21 mm Total no of fins used: 227 Length of fin: 350 mm Width: 28 mm Pitch: 14 mm Transverse pitch: 12.82 mm Staggered offset: 7 mm Single Fin Area: 6873.51 mm2

Surface area of single fin: 14380.9 mm2

Total surface area of 227 fins (AF): 3264464.3 mm2


AF=3264464.3 mm2

AF= Total surface area of 227 fins Aw=Surface area of the tube between the fins=Nf×∏×Dr×leff Nf=No. of fins=227 leff=290-(.21×227)=242.33mm

Figure 44

Aw=1178602.307 mm2

A=AF+Aw=4443066.607mm2

AT=the total external area of the tube without fins AT=NT×L×∏×Dr=49×300×∏×6.82 =314957.2299mm2

Va=17m/s



Mass flow rate of air (ma) = Va×ρa×AFR AFR=Frontal area of the radiator through the air passes AFR=(290×350)-(350×0.21×227)=84815.5mm2

ma=10×1.145×84815.5×10-6

=1.650934 kg/s The corresponding Reynolds no. Re a=Va× Dr× ρa/µ = (10×6.82×10-3×1.145)/ (1.895×10-5) =7005.345646 The air side heat transfer coefficient is obtained using the ESDU CORRELATION for high fin staggered array heat exchanger: CALCULATION OF NUSSELT NUMBERS ON AIR FLOW: Nua=0.242× (Re a

0.688) ×(s/h)0.297×(p1/p2)-0.91×Pr1/3

=0.242× (7005.3456460.688) ×(1.4/3.75) 0.297×(14/12.82)-0.91×(0.72681/3) =66.288228 Air side heat transfer coefficient: ha=ka×Nua/Dr =0.02625×46.00883/(6.82×10-3 )

=255.141639w/m2k Efficiency of the fins: ηf={tanh(√(2ha/(w× kf) ×Ψ)}/(√(2ha/(w kf) ×Ψ) Ψ= Dr/2[{(wf/2)/ Dr}-1][1+0.35ln{(wf/2)/ Dr}] =6.82×10-3/2[(14/6.82)-1][1+0.35ln(14/6.82)] =4.4936×10-3

W=2.1mm (width of fin)Kf=237 w/m.k

(√ (2ha/(w kf) ×Ψ)=.0295156 ηf=.999885

The effective air-side heat transfer coefficient based on total surface area is given by- ha

!=( ηf×AF×Aw/A)ha =220.916239 w/m2.k The air side heat transfer coefficient referred to the external surface to the tube without fins: ha r= ha

!(A/AT)=3116.441292 w/m2.k Coolant side heat transfer coefficient: CALCULATION OF NUSSELT NUMBERS ON COOLANT SIDE:

The Nusselt number on coolant side depends primarily on coolant

flow conditions. The coolant flow inside the radiator core can be considered as fluid

flow in pipes. Thus, the coolant flow can be laminar, transitional or turbulent, each

being characterized by the appropriate Reynolds number. The coolant flow is nor-

mally laminar when the Reynolds number is below about 2,100. In the range of

Reynolds numbers between 2,100 and 4,000, the coolant flow is transitional. At a

Reynolds number of about 4,000 the coolant flow becomes fully turbulent. The

quoted Reynolds numbers are approximate and could vary under different radiator

constructions.

Nusselt Numbers for Laminar Coolant Flow:

For laminar flow, the equation for laminar flow in tubes proposed by

Hausen was used. Hausen's equation can be written as:

Nusselt Numbers for Turbulent Coolant Flow:

For turbulent flow, the empirical equation developed by Dittus and

Boelter in 1930 for fully developed turbulent flow in tubes was used. The Dittus and

Boelter's equation can be expressed as:


Nusselt Numbers for Transitional Coolant Flow:

For transitional flow, a equation cited by Achaichia was also used to

calculate the Nusselt Numbers in transitional flow. The equation can be written as:

ρc=1070 kg/m3

Vc=0.8 m/s µc=0.00156025 Ns/m2

internal dia of tube with turbulator=5.29mm Reynolds no: Re c=Vc×Dhc× ρc/µc =2902.252844 Prc =29.13 The Reynolds no. represents the flow is transient:

=35.879477 kc=.4685 w/m.k hc=(Nuc×kc)/ Dhc =3177.605847 w/m2.k Mass flow rate of coolant (mc) =NT× Vc×ρc×Atube, internal NT=No. of tubes mc=49 ×1×1070×∏/4× (5.29×10-3)2

=0.921873kg/s Fouling resistance for engine water: RF=0.000175 m2.k/w


Overall heat transfer coefficient: Assumption: The thermal assumption at junction of fins & tubes are neglected. Hence, the value of Ur ,related to the external surface of the tube without fins, i.e. to dia. Dr 1/Ur=Rf+ 1/ha r+ (Dr/2ktube) ln(Dr/ Dhc)+1/hc Ur =1228.144626 w/m2k NTU=AUr/Cmin =4443066.607×10-6×1228.144626 / (1.650934 ×1007) =3.282262 R=Cmin/Cmax= (1.650934×1007)/ (0.921873×3383) =0.533072 RADIATOR HEAT TRANSFER EFFECTIVENESS:

For a cross-flow heat exchanger with both fluids unmixed, the problem

of determining the heat transfer effectiveness is very complicated even in the case of

a single pass exchanger. Very little information about the heat transfer effectiveness

for this kind of flow has been published. Mason [12] developed an analytical solution

that is very difficult to use.

Besides Mason's analytical solution, an approximate equation used

By many authors to calculate the heat transfer effectiveness of a cross flow heat

exchanger with both flows unmixed has been used.

R R

=0.835025

=0.835025×(1.650934×1007) =1388.22 w/K


In practical cases; Q=.5×SD× (Thot, in- Tcold, in) =.5×1388.22× (92-27) =45.126 kW Tc, i-Tc,o=Q/CmaxTc,out= Tc ,in- Q/Cmax =77.53 0C Ta,o-Ta,i=Q/Cmin Ta,o=54.144160C


FEM Generation of Parts (Through pro/Engineer):

Fin

Round Tube

Header Turbulator

Lower Tank Fan



ANSYS Analysis

ANSYS Analysis

Air flow pattern over the round tubes (Through ANSYS)

Velocity Distribution:

Contour plot:

Figure B1


Close view of contour plot

(Vsum)


Figure B2

Figure B3

V

Pressure Distribution over the tubes


FigureB4

x Plot

Figure B5

Vector Plot:


Figure B6

Figure B7

Flow Trace (particle flow):


Figure B8

Temperature Distribution over the tubes: Contour Plots:


Tube with uniform temp 700C

Close view

FigureB9

Figure B10

Over the Aluminium fin:

Heat Flux:

Contour Plot


Figure B11

m

Contour Plot

Vector Plot Figure B13


Figure B12

Tube:

Contour Plot

Figure B14

Vector Plot

(At entrance Region)


FigureB15

Figure B16

(At exit Region)

(Temp Distribution)


FigureB17

Air Velocity/pressure distribution over the car:

Contour Plot

Figure B18

Vector Plot

Figure B19


Pressure Distribution Figure B20

Node representation

Figure B21


Particle flow

Figure B22

Figure B23



Simulation Program


Simulation Program

#include<iostream.h> #include<conio.h> #include<graphics.h> #include<math.h> void main() { clrscr(); int gdriver = EGA, gmode = EGAHI; initgraph(&gdriver, &gmode, "c:\\tc\\bgi"); setbkcolor(BLUE); outtextxy(200,30,"ALL THE DIMENSIONS ARE IN MM"); long float NT,L,Dr,Di,Lf,Tf,NF,AF=3264464.3,l_eff,A,Aw,Pi=3.141592,wf ,a,AT,di,Lc=300,SD ; cout<<"\n\n\nEnter total no of tubes\n"; cin>>NT; cout<<"\nEnter length of tube\n"; cin>>L; cout<<"\nEnter outer dia of tube\n"; cin>>Dr; cout<<"\nInternal dia of tube\n"; cin>>Di; cout<<"\nInternal dia of tube with turbulator (Hydraulic Diameter)\n"; cin>>di; cout<<"\nEnter the length of fin\n"; cin>>Lf; cout<<"\nEnter the thickness of fin\n"; cin>>Tf; cout<<"\nEnter the width of fin\n"; cin>>wf; cout<<"\nEnter the total no. of fins\n";


cin>>NF; l_eff=290-(Tf*NF); cout<<"\n\nSurface area of the tube between the fins\t"; Aw=NF*Pi*Dr*l_eff ; cout<<"Aw="<<Aw; A=AF+Aw; cout<<"\n\nThe total external area of the tube without fins\t"; AT=NT*Lc*Pi*Dr; cout<<"AT="<<AT; long float AFR,Ma,Vmax,P_air=1.145,Gw , Ge ; cout<<"\n\nEnter the velocity of air (m/s)\n"; cin>>Vmax; cout<<"\n\nFrontal area of the radiator through the air passes\t"; AFR= (290*Lf)-(Lf*Tf*NF) ; cout<<"AFR="<<AFR; Ma=Vmax*P_air*AFR*pow(10,-6); cout<<"\n\nMass flow rate of air(Ma)="<< Ma; long float Ga=0.00001895,Re_air,Nu,z,fct,Ef,ha,ha1 , Pr=0.7268,s=1.4,h=3.75,p1=14,p2=12.82, kf=237; cout<<"\n\nThe corresponding reynold no\t"; Re_air=Vmax* Dr*pow(10,-3)* P_air/Ga; cout<<"Re_air="<<Re_air; cout<<"\n\n\nPress any key to continue........................."; getch(); cout<<"\n\nThe air side heat transfer coefficient is obtained using the" <<"\nESDU CORRELATION for high fin staggered array heat exchanger";


Nu=0.242* pow(Re_air,0.688)*pow((s/h),0.297)*pow((p1/p2),-0.91)*pow(Pr,(0.333)); cout<<"Nu="<<Nu; cout<<"\n\n Air side heat transfer coefficient\t"; long float ka=0.02625,V_coolant,ha_r; ha=ka*Nu/Dr*pow(10,(3)); cout<<"ha="<<ha; z= Dr*pow(10,(-3))/2*((14/Dr)-1)*(1+0.35*log(14/Dr)); fct=pow((2*ha/(wf*kf) *z),(0.5)); Ef=(tanh(fct))/(fct); cout<<"\n\nEfficiency of the fins:\t"<<"Ef="<<Ef; cout<<"\n\nThe effective air-side heat transfer coefficient" <<"\n based on total surface area is given by\t"; ha1=(Ef*AF*pow(10,-6)*Aw/A)*ha; cout<<"ha1="<<ha1; cout<<"\n\n\nPress any key to continue........................."; getch(); cout<<"\n\nThe air side heat transfer coefficient referred to "<<"\nthe external surface to the tube without fins:"; ha_r=ha1*(A/AT); cout<<"ha_r="<< ha1*(A/AT); long float p_coolant=1070 ,G_coolant=0.00156025,Re_coolant,h_coolant,k_coolant=0.4685,Nu_coolant, A_tube_internal,M_coolant,Pr1= 29.13,a1,a2,a3,a4; cout<<"\n\nWater side heat transfer coefficient:\n"; cout<<"\n\nEnter velocity of coolant:\n"; cin>>V_coolant; cout<<"\nReynolds no:\t"; Re_coolant=V_coolant*di*pow(10,-3)* p_coolant/G_coolant; cout<<"\Re_coolant="<<Re_coolant ;


if(Re_coolant<2300) { a4=(di/L)*Re_coolant*Pr1; Nu_coolant=3.66+((0.0668*a4))/(1+0.04*pow(a4,0.6666)); } if((Re_coolant>=2300) && (Re_coolant<=4000)) { a1=1+pow((di/L),0.89); a2=1.8*pow(Pr1,0.3)-0.8; a3=pow(Re_coolant,0.8)-230; Nu_coolant=0.0235*a3*a2*a1; } if(Nu_coolant>4000) { Nu_coolant=0.023*pow(Re_coolant,0.8)*pow(Pr1,0.4); } cout<<"\n\n Nu_coolant="<<Nu_coolant; h_coolant=(Nu_coolant*k_coolant)/di*pow(10,3); cout<<"\n\nh_coolant="<<h_coolant; cout<<"\n\n\nPress any key to continue........................."; getch(); cout<<"\n\nMass flow rate of coolant (M_coolant)\t"; A_tube_internal= Pi/4*di*di*pow(10,-6); cout<<" A_tube_internal="<<A_tube_internal; M_coolant =NT* V_coolant*p_coolant*A_tube_internal; cout<<"M_coolant="<<M_coolant; long float RF=0.000175 ,T_coolant_in=92.0,T_coolant_out=30.0,k_tube=237;


cout<<"\n\nOverall heat transfer coefficient "; cout<<"\n\nAssumption: " <<"\n\nThe thermal assumption at junction of fins & tubes are neglected " <<"\nHence, the value of Ur ,related to the external surface of the tube without fins, i.e. to dia. Dr"; long float sd,Ur,T_air_out,T_air_in=27,C_min,C_max,e,Q,R,DTm, NTU_air,Cp_coolant=3383,Cp_air=1007,exp=2.718281828,x1,y1; sd=RF+ 1/ha_r+(Dr/(2000*k_tube))*log(Dr/di)+1/h_coolant; Ur=1/sd; cout<<"\n\n\nPress any key to continue........................."; getch(); cout<<"\n\n\nOverall heat transfer coefficient\t"; cout<< Ur; C_min=(Ma*Cp_air); NTU_air=A*pow(10,(-6))*Ur/C_min; cout<<"\nNTU_air="<<NTU_air ; C_max=(M_coolant*Cp_coolant); R=C_min/C_max; cout<<"\n\nR="<<R; y1=pow(NTU_air,0.22)/R; x1=pow(exp,(-R*pow(NTU_air,0.78)))-1; e=1-pow(exp,(x1*y1)); cout<<"\n\nEffectiveness:"<<e ; SD=0.5*e*C_min; Q=SD*((T_coolant_in)-(T_air_in)); cout<<"\n\n Q(watt):"<<Q;


T_coolant_out= (T_coolant_in)- (Q/C_max); cout<<"\n\nOutlet temp. of coolant="<<T_coolant_out; T_air_out=(Q/C_min)+T_air_in; cout<<"\n\nOutlet temp. of Air="<<T_air_out; getch(); closegraph(); }


ADVANCEMENT:

Improvement is an endless phenomenon. The same is true for different outcomes

of different manufacturing concerns, which required continuous improvement to withstand

the global competition in the market .

Thatswhy the aim which we have taken as our responsibility is not fulfilled completely.

What we have done is just an initialization and there is a lot to still now.

On the basis of the theory we have explained more mathematical models can be

developed that can be solved by computer and more information can be added about the

reasons of reduction in efficiency.

In the current advancement the composite aluminium foil used for radiators is a

core of Al-Mn alloy sandwiched by Al-Si brazing material, made through hot rolling

composite technology. This product is mainly used on fins of automobile heat

exchanger, requiring not only an excellent surface quality, accurate dimension and

flat contour, but also uniform structure, good forming performance, and in particular

the uniformity of the covering layers and brazing features.

Brazed composite aluminium foils are a type of new aluminium alloy of high

performance among the top brands of aluminium process products, characterized by

its high technical content and value added. Such sandwich structure of composite

aluminium foils, possessing properties of light weight, corrosion resistance, good

brazing features and reliability has been widely applied in automobile heat

exchangers, such as automobile water tanks, condensers of automobile air

conditioners, and evaporators.

We can improve design of tubes in the following manner as shown below:

Internally and externally finned tubes (Enhancement)


Internally and externally finned tubes (Enhancement)



Conclusion

After passing so many hurdles finally we achieve our target to

minimize the design time of cooling system by preparing a simulation model in form

of a mathematical model. That can be solved by using a digital computer.

The computer program that is attached in the “project”

could give results or effects of change in different parameters and thus helps in

design.

We also got success to explain the causes of downfall of effectiveness of

radiator (heat exchanger).

Thus we have constructed a platform (simulation program) to further

proceed for betterment in form of efficient design cheaply in least possible time and

improved effectiveness.


APPENDIX

T

RADIATOR DURABILI Introduction: The combined p

the real vehicle running c

radiator durability test. Th

separation. Metal or plasti

facility for conducting the

The user will have the faci

and vibration test at the sam

COMBINED PRESSURE

Procedure:

On clicking the “

specified window. Here

configuration- here he ca

coolant temperature and nu

Radiator vibration configu

cycle can, be set over here

and no. of cycle can be set

To set start the test user ha

up by pressing various b

“coolant flow start”, “heate

has to press “process mon

the specified form. Here p

would be able to see the t

before radiator and pressur

extreme right hand side.

“Quit” button stops the tes

Durga Shankar

APPENDIX A

ESTING OF RADIATOR

TY TEST

ressure and vibration cycle test rig is defined to simulate

ondition as for as the radiator is concerned. It is for the

is rig would provide data/observation related to leak, braze

c fracture of radiator and hose. This set up will have the

burst pressure test with water and air pressure cycle test.

lity to run the program for burst pressure test and pressure

e time (either together or singly) through the PC.

AND VIBRATION TEST:

CPV test” button in the main menu, user reaches the

he can set various test conditions. Pressure cycle

n set the start value of pressure, rise value of pressure,

mber of cycles.

ration – amplitude of vibration, acceleration and number of

. Hose vibration configuration- here amplitude, frequency

over here.

s to press “start test” button. All the testy condition are set

uttons-“radiator vibration start” , “hose vibration start”,

r on”, “pressure cycle start”. To show resulting graph user

itoring and control” tab, due to which window changes in

ressure after radiator value is displayed on the graph. User

otal pressure cycles, frequency, tank temp., temp after and

e after and before radiator on the indicator provided on the

t and takes the application back to the main menu.

[email protected] - 108 -

BURST TEST:

Procedure:

When the user clicks on the “burst pressure test” button the main menu then he

reaches the specified window. Here he select the rise time (time required for the

pressure to increase) no. of cycle, rise value (maximum pressure to be reached) and

slab time (Time for which pressure stays at a particular value).

Now to start the test it would be required to fill the water in the radiator by pressing

the “fill water” button. This will disable the control variables, this process fills the

radiator with water. Now when “start test” button is pressed, pressure starts building

up in steps till the radiator bursts.Pressure indicator will allow him to see the change

in pressure during the run time.

“Quit” button will take him back to the main menu.


AIR PRESSURE CYCLE TEST:

Procedure:

On pressing the “air pressure cycle” button in the main menu, user reaches the

specified window. Here in the beginning user provides the control variables-“start

value” of pressure, “rise value” of pressure and then “fall value” of pressure, “slab

time(time for which pressure remains at a particular level) and the “no. of cycle” for

which this process should go on.

Then he starts test by clicking the “start test” to start the test.

Two indicators are provided which show the status of the test in the

running condition. These are “no. of cycle completed” and “pressure created”.

“Quit” button will stop the test and brings back to the main menu.


TENSILE TESTING MACHINE:

Application: tensile test

Speed: 10% to 100%

Max. Capacity: 500 KGF

Tensile stress:

This is the stress which occurs on the material tangentially. It may be in both

the directions horizontally & vertically. In this type of stress both the sides of the strip

are undergo to the deformation due to the stress but in the opposite direction to each

other.

The tensile test machine is used to check out the strength of the epoxy joint

which is mostly used in both the radiators MAAR & CAB to joint the round

&elliptical tubes respectively with the header by means of epoxy.

It is used to measure the maximum load in KN on which the epoxy joint can with

stand without got failed at that one. Applying this tensile testing machine we can

declare the factor of safety for the joints with the tubes.

OPERATING PROCEDURE:

• Switch on main.

• Fit the strip in the upper & the lower clamp according to the mark on the

strip. By using the button rapid + up or rapid + down as per the requirement.

• Switch on the tensile machine.

• Ensure that the reading of the machine in KN get the zero reading in the

beginning of test.

• Set the speed (it is normally 10%) by pressing “speed selector” button.

• Press the “test” to start the test.

• Wait for the disconnected of both the strip.

• Note down the reading when the strips are got separated by pressing the

PARA button two times.



• Switch off the tensile testing machine.

• Switch off the main.

SALT SPRAY CHAMBER:

Application : Salt spray

Chamber Temp. : Ambient to 80

Solution Temp. : 35 to 55C

Accuracy : 1C

Humidity : 95%RH

Accuracy : 3%

This is the chamber in which we have the mixture of water (H2O) & salt

(NACL) in Standard quantity which is specified in the specification. Usually we take

95% RO water with 5%of salt in the chamber. It is basically used for checking the

rusting period of the material at which it undergoes to the oxidation or we can say

corrosion of that particular material. This is done by the sprayed out the salt (NACL)

on the material which we stabled in to the chamber it. It occurs due to continue

sprayed out the steam of salt & water .The chamber should be perfectly closed when

it is in the operating condition. By the use of this salt spray chamber we can declare

the factor of safety for under go to oxidation. Before this period the material does not

under go to the oxidation.

SALT SPRAY CHAMBER OPERATING PROCEDURE:

• Before starting the main chamber check following points.

• Fill the air saturating tower with distilled water (RO water) .To fill saturating

tower, ensure the air supply is stopped and ball valve of saturating beaker is

open. Fill beaker with distilled water. After filling close ball valve.

• Take 95 it’s of distilled water (RO water) 5kg NACL mix properly.

• Filter and fill the solution in the solution tank.

• Check the entire inter connection pipeline between the main chamber and the

panel.

• See that sufficient water fill inside the wick tank and also that wick filled

for wet bulb sensor is dropped inside the wick pan.


• Load specimen parallel to flow of salt spray. Please check specimen is

away from chamber wall.

• Close top cover of chamber and add water in cover channel for sealing.

• Switch on the mains.

• Set the desired temperature of chamber that is 39C, set solution tank at 35C

and saturation temperature at 50C on controller by pressing the set point knob.

• Switch on the saturated tower heater, hot air tower and solution tank heater

switch.

• Adjust the air pressure on FLR, as per test requirements. Air pressure is

between 1~1.5 kg / cm2. It is dependent on solution collection (1~3 ml/hr) in

beaker this can be checked in 24 hours and recorded. Air flow can

change dependent on collection in beaker.

• Note the starting hour from hour meter.

• It buzzer on fill the desired tank.

TWIST AND TORSION TWISTER:

Application : twist and torsion

Max. Frequency : 100 HZ. Max.

Acceleration : 50g

Displacement : 10mm up & down max.

TWIST TEST RIG OPERATING PROCEDURE:

• Turn on the main power switch of the control unit.

• Fix lower tank and upper tank of radiator on the test rig fixture and tight

properly. Set amplitude with the help of dial button side of fixture as requested

special sample inspection request or as per drawing specification.

• Adjust for amplitude by adjusting the eccentricity of button mounting fixture

rig.

• Set duration on counter as requested or as per drawing specification.

• Set RPM for cycle time from speed regulating knob.

• Set amplitude, duration and cycle time as requested or as per drawing

specification.


• Press reset button and put start button ON.

• After completion of duration cycle machine will stop automatically.

• Remove sample from rig and test for leak as requested. Also observe the

sample for any kind of physician deformation and report if any.

• Enter result in twist test database and print the result.


THINGS TO DO FOR SMOOTH RADIATOR WORKING:

• Always use the MUL approved coolant.

• Use distilled water in right ratio with the coolant.

• Maintain the correct coolant concentration (70% distilled water / 30%

coolant)

• Do not mix coolants grade e.g. Golden cursier with Coolex or mixing of

blue & green coolant?

• During washing of radiator make sure that jet pressure is not high. It

should not damage the fins.

• In case radiator is taken out & turned upside down, make sure that the

Tabulators (springs) don’t fall.

• Make sure the drain cock is tightly closed all the time.

• Do not use any cleaning agent(Acid/Alkaline) to wash the inside of the

radiator

• Do not open the crimping at any point in time.


BENEFITS & FEATURES: Features Benefits Efficient heat transfer capabilities through dimpled tubes and louvered fin designs.

Provides package efficient heat transfer capability

Long life and high strength aluminium alloys

Provides corrosion resistance Offers compatibility with high pressure coolant systems Offers compatibility with numerous long life coolants such as GO5

Integrated plastic tank features such as fasteners and ports

Offers flexible vehicle mounting Reduces tooling expense and product weight

Seamless hose connector Enables use of in-tank transmission oil coolers Improves concentricity and reduces joint leakage

One shot brazed radiator with aluminium tanks

Provides full recyclability and leak free performance

Flexible core dimensions and a large selection of available core depth

Offers package flexibility

APPENDIX B

Maintenance and Tech Tips: Cooling System:

Aside from the water pump, there are three main components of a vehicle’s engine

cooling system: the radiator, heater core and coolant. Although these three components have no

moving parts, their maintenance is vital for long-term durability and vehicle performance.

What is even more critical is how important their roles in overall vehicle operation have

become with today’s complex systems.

Like most consumers, many follow the adage, “if it’s not broke, don’t fix it,” and

only address their engine cooling system after it’s too late. Unfortunately, by this

time, the damage is already done and they may be looking at a sizeable repair bill and

a lot of inconvenience. For those customers who do take an active part in vehicle

maintenance, it’s important to stress that some preventive medicine is necessary and

there is a difference in the replacement components and repair services they choose.

Here are a few preventive service tips anyone can perform at least once a year

to keep their engine cooling systems running at peak performance:

• Inspect all connections and components for leaks.

• Inspect all hose clamps and fittings; tighten if necessary

• Inspect all hoses and belts and replace them if they are cracked, worn or

deteriorated.

• Never use tap water when adding a 50/50 mixture of coolant/water to the

vehicle. Always use distilled or demineralized water to prevent corrosion.

• Be sure your coolant level is at the appropriate level, top it off only with a

50/50 mix of the OE coolant type and distilled or demineralized water.

• Check the condition of the radiator cap and replace it if the gasket is worn.

• If engine temperature varies from running too hot or too cool under

normal operating conditions, a faulty thermostat or cooling fan may be the

problem. Proper fan speed must be maintained to keep air flowing

consistently through the radiator. Faulty electronic control units can cause

the fan RPM to vary.



Cooling System Tune-Up Checklist:

CAUTION: NEVER REMOVE THE RADIATOR PRESSURE CAP WHILE THE

ENGINE AND COOLANT ARE STILL HOT.

ONCE THE ENGINE HAS COOLED, REMOVE THE CAP VERY SLOWLY.

Your vehicle’s cooling system protects your engine against heat generated during

normal operations by keeping the engine operating within the correct temperature

range. If the cooling system is not operating properly and the temperature range is

exceeded the engine can be damaged. Regular checks and maintenance help assure

long life of vulnerable engine parts.

The cooling system maintenance schedule recommended by the vehicle manufacturer

should be followed.

Here are some of the basic steps in proper cooling system maintenance:

Check the condition of the water pump by inspecting for coolant leaks and by

checking the pump shaft for “play” which may indicate excessive wear. If either of

these conditions exists you may need to replace the water pump.

• Inspect the radiator for leaks and corrosion

• Be sure your radiator coolant level is maintained at the manufacturer’s

recommended level.

• Look for leaking hoses, fittings, and connections. Tighten loose clamps.

• Inspect condition of hoses. Cracked, mushy or otherwise deteriorated

hoses should be replaced.

• Check condition of the radiator pressure cap. Replace if rubber gasket is

damaged.

• If the engine runs too cool or hot, the thermostat, fan or fan clutch may be

at fault and should be replaced. The temperature gauge reading outside

the normal range may indicate this condition or the check engine light may

be on. Check your service manual to evaluate their performance.

• Heater hoses demand attention too. Look for leaks, cracks or rotted

rubber. Replace faulty clamps.


• Check belts for wear and tension. Replace when cracked or frayed.

When Replacing A Radiator:

Many reasons cause a radiator to fail. Here are a few steps that will help

prevent comebacks.

• Always ask yourself what caused the radiator to fail. Check all possible

causes for the radiator deterioration.

• Inspect radiator cap with tester. The radiator cap increases the boiling

point of the coolant and ensures a constant level of coolant in the radiator.

• Thoroughly flush the system including the heater core and overflow

container. Any residue in the system may contaminate the new coolant and

cause premature failure.

• Install a new thermostat. Keeping the temperature right is what it’s all

about… install the right temperature range thermostat.

• Inspect hoses and install new clamps.

• 50/50 mix of antifreeze and clean water (distilled water is recommended if

water treatment in the region shows high signs of by-products). This mix

will provide protection against boiling and freezing temperatures while

providing maximum corrosion protection.

• Once the work is completed, run the engine long enough for the electric

cooling fans to turn on or inspect the mechanical thermal clutch fan for

proper engagement. Cooling fans are crucial for proper system operation

and preventing cooling problems at low speeds. For electric cooling fans,

see manufacturer specification in the shop manual as most vehicles use the

on-board computer via the engine coolant temperature sensor to turn on

the fans.

• Ensure the drive belts, specially the one that runs the water pump is tight

and in good condition.


Heater Core Installation Guidelines:

When installing a new replacement heater core, it is important to remember that

heater core installations vary from car to car, and the following is intended only as a

guide. Consult the owner’s manual or vehicle specific repair manual for detailed

instructions.

The basic tools required for the typical installation of a new heater core are a

screwdriver, a set of open-end wrenches and a pair of pliers. It is highly

recommended that you replace your heater core hoses, hose clamps, thermostat and

radiator cap.

• After removing the failed heater core from the vehicle, find out why it failed:

is it the original heater core? Was it replaced before? If so, how long ago? If

the heater core has been replaced within the last 6 months, you may be

looking at a cooling system problem, not a heater core problem. What is the

condition of the coolant: color? PH? any residue in the radiator fill neck?

The color should not be muddied or “rusty” in appearance. The pH should be

in the range of 7.7 – 11.0. And the mix should be 50/50. Test the heater core

for leaks: pin hole leaks in the core could be a sign of Electrolysis. This

condition is usually a result of add on equipment – stereo amplifiers, alarm

systems, plow lifts, etc. that have not been properly grounded to the vehicle.

You can test for this by using a DC voltmeter to submerge the positive lead

into the radiator fill neck and ground the negative lead at the battery. This

should be done with the radiator cap off and the engine running. You should

not read any more than 0.1 volt. Any higher reading is cause for alarm and

the offending component must be found and grounded properly. Stray

excessive electrical current can destroy an aluminium heat exchanger in a very

short time.

• Once you have determined that the system is OK, it is strongly recommended

that you flush the cooling system thoroughly and aggressively before you

install the new heater core. Multiple flushings are not out of the question to

assure proper system chemical balance, especially if you suspect poor coolant

condition was the root cause of the previous failure. A flush machine is

preferred, but flush aggressively to the best of your ability.


• Carefully re-install the heater core following the removal and additional steps

listed above. Caution!! Heater pipes that are long can create destructive

forces to the connection joint at the tank, if excessive force is applied to these

pipes during the installation process. Be careful when inserting the heater

core into the mounting housing to avoid over stressing the connection joints.

• Fill the system with a new 50/50 solution of the proper coolant and deionized

or distilled water as recommended by vehicle manufacturer. Coolant pre-

mixes may also be used. Be sure to replace your coolant with the same kind

that was removed (refer to your owner’s manual to identify the coolant used in

your vehicle). Tap water is lethal to aluminium components in a cooling

system. Replace the pressure cap.

• Start engine to check for leaks. After the engine has idled long enough to

open the thermostat (engine should reach it’s normal operating temperature),

turn the engine off. Make sure the cooling system has cooled down before

slowly removing the pressure cap to check the coolant level: add the 50/50

mix or pre-mix as needed to bring the coolant level to the bottom of the fill

neck or to the appropriate level in the overflow tank. Replace the pressure

cap.

• Check the coolant recovery reservoir the next few times you drive the vehicle,

and, if necessary, add enough coolant mix to bring it up to the proper level.

Radiator Installation Instructions:

• The replacement radiator is installed by following the basic steps listed below.

Please keep in mind that the radiator installations vary somewhat from car to

car, and that the following is intended only as a guide. Consult your owner’s

manual or a vehicle specific repair manual for detailed instructions.

The basic tools required for the typical installation of your new radiator are a

screwdriver, a set of open-end wrenches and a pair of pliers. We highly

recommend that you replace your radiator hoses, hose clamps, thermostat and

radiator cap


REMOVAL:

• Slowly remove the pressure cap and save for later use, or better yet, purchase

a new pressure cap designed specifically for your vehicle.

• Drain the coolant from the system through the drain cock, if so equipped, or

by removal of the bottom radiator hose. Replace the coolant with new coolant

to protect your new radiator. Normal coolant replacement should be every (2)

years. Be sure to discard used coolant in a safe manner and according to

government disposal regulations. Failure to use the proper new coolant can

void your warranty.

• If the radiator has a transmission and/or an engine oil cooler, use a line

wrench to disconnect the lines from the radiator tanks. Before disconnecting

any oil cooler lines be sure to identify where these line are connected and

mark them, so they can be re-connected properly to the new radiator. Care

should be taken to avoid stripping the fittings or kinking the transmission or

engine oil cooler fluid lines. To avoid fluid loss, block the ends of the lines

after removing them from the radiator fittings.

• Remove the upper mounting panel and associated sheet metal.

• Remove the fan shroud or electric fan assembly screws and remove the part,

or slide it back away from the radiator far enough to permit removal of the

radiator.

• Disconnect the radiator inlet and outlet hoses, and heater

bypass hose (if so equipped) from the radiator hose fittings. Check for

brittle or deteriorated hoses. New hoses, clamps, and thermostat are strongly

recommended.

• Remove any sensor fittings attached to the radiator tanks, noting the exact

location so that proper replacement can be made with the new radiator.

• Remove the top mounting insulators, or the bolts from the radiator mounting

brackets, if so equipped.

• Remove the radiator assembly from the vehicle. NOTE: The installation of

some high capacity replacement radiators may require trimming of the rubber

mounting insulators to facilitate installation.


INSTALLATION:

Reverse this procedure for the installation of the new radiator. Start to thread

transmission or engine oil cooler lines into the cooler fittings carefully by hand to

avoid stripping threads. NOTE: As a tip, it is often better to leave the mounting

bolts loose until all the hoses and lines are connected. Improper installation (cross

threading) of the oil cooler lines that results in stripping of the internal threads

will void the manufacturer’s

1. warranty Tighten the fittings with a line wrench. Be sure to connect all the

lines to their proper location in the radiator tanks and tighten securely.

Carefully retighten any connections as required: NOTE: Avoid over-torquing

the drain plug; only hand tighten. Do Not use any tools to tighten the plug as

damage to the threads will result. With the engine idling, recheck the

automatic transmission fluid level.

2. Fill the system with a new 50/50 solution of the proper coolant and deionized

or distilled water as recommended by the vehicle manufacturer. Coolant pre-

mixes may also be used. Be sure to replace your coolant with the same kind

that was removed (refer to your owner’s manual to identify the coolant used in

your vehicle). Replace the pressure cap. Start engine and check for leaks.

3. After the engine has idled long enough to open the thermostat (engine should

reach it’s normal operating temperature), turn the engine off. Make sure the

cooling system has cooled down before slowly removing the pressure cap to

check the coolant level: add the 50/50 mix or pre-mix as needed to bring the

coolant level to the bottom of the fill neck or to the appropriate level in the

overflow tank. Replace the pressure cap.

Check the coolant recovery reservoir the next few times you drive the vehicle,

and, if necessary, add enough coolant mix to bring it up to the proper level.


Pro/engineer wildfire 2.0

APPENDIX C

Pro/engineer wildfire 2.0 is a powerful program used to create

complex design with a great precision. The design intent of any three dimensional

model or an assembly is defined by its specification and its use. We can use the

powerful tools of pro/engineer wildfire 2.0 to capture the design intent of any

complex model by incorporating intelligence into the design.

To make the design process simple and quick, this software package has divided the

steps of designing into different modules. This means each step of designing is

completed in a different module. For example, generally a design process consists of

the following steps:

• Sketching using the basic sketch entities.

• Converting the sketch into features and parts.

• Assembling different parts and analyzing them.

• Documentation of parts and assembly in terms of drawing views.

• Manufacturing the final part and assembly.

All these steps are divided into different modes of pro/engineer wildfire 2.0, namely,

the sketch mode, part mode, assembly mode, drawing mode, assembly mode,

manufacturing mode.

In spite of making various modifications in a design, the parametric nature of this

software helps to preserve the design intent of a model with tremendous ease. Once

we understand the feature-based, associative and parametric nature of pro/engineer

wildfire 2.0, we can appreciate its power as a solid modeler. It allows us to work in a

3D environment and calculates the mass properties directly from the created

geometry. We can switch to various display modes like wire frame, shaded, hidden

and no hidden at any time with ease as it only changes the appearance of the model.


ANSYS This is very useful package with bi-linear elements, heat transfer analysis and

fluid flow. This package can be used as a pre-and-post processor.

Perhaps the greatest advantage those ANSYS offers its users is its

incredibly wide range of capabilities. ANSYS not only provide all the functions that

engineer and scientist expect in an analysis program such as variety of analysis types,

material representation, and a comprehensive library of element, it offers much more.

some of the additional features include pre-and-post processing, on line

documentation, design optimization, solid modeling and three dimensional graphics.

The following analysis capabilities are available in ANSYS.

Static analysis:

Linear static analysis assumes that structural equilibrium equation and

material properties are linear.

Non linear static allows for non linear behaviour in both geometry and

material. large deflection, stress stiffening, plasticity,creepand interface conditions

can be included in analysis.

Dynamic analysis:

Linear transient dynamics efficiently solves for the response of a linear

structure.

Non linear transient dynamics incorporate material, geometric and

interface non linear effects.

Spectrum analysis envelopes the dynamic response to random vibration

or seismic loading.

Harmonic response determines the steady state response of a linear

structure subjected to harmonically time varying loads.

Mode frequency:

It computes the natural frequencies and associated mode shape of a linear,

undamped structure.


Stability analysis:

Linear eigenvalue buckling determines the critical loads and the associated

buckled shapes for a linear structure.

Large deflection analysis the limit load, whether failure occurs by bifurcation or

snap through buckling.

Heat transfer:

Linear heat transfer assumes non temperature dependent material

properties.

Non linear heat transfer can have temperature dependent material

properties and can include radiation and temperature dependent convection

boundary conditions.

Transient heat transfer solves the time dependent temperature distribution

with in a body. non linear effects may be included.

Magnetostatics:

It solves for the intensity and flux density of a magnetic field due to

current source and permanent magnetic materials.

Coupled Field analysis:

Simultaneously solves interacting multiple field effects including two or

more of the following: structural displacement and forces, temperature and heat

flows, electric voltage and current, magnetic intensity and flux and confined fluid

flow pressure and velocity.

Global/Local Modeling:

Sub structuring physically by cutting a piece or multiple pieces of a model

and generating corresponding substructures for use in the full analysis at

substantial cost saving.

sub modeling uses the result of a coarsely - modeled structure to obtain an

accurate solution of a locally refined sub model.


Material representation:

A wide variety of material representations are possible with ANSYS.

Material properties may be temperature dependent, isotropic, orthotropic,

anisotropic. Non linear material behavior such as plasticity, creep, swelling and

non linear elasticity both available in both static and dynamic analysis. plasticity

material option include:

The von-mises yield criterian coupled with kinemtic hardening which

represents most metal behaviour very well in the plastic range.

Anisotropic plasticity which allows for different stress and strain

behaviour in different direction as well as different behaviour in tension and

compression. this option can be used for composites or the matal in which yield

strength is affected by processing.

Drucker-prager in which the material strength is dependent on the

confinement pressure such as for granular materials.

APPENDIX D

Radiator Dimensions Measurement:

Radiator types and configuration:

The down flow radiator is designed so coolant flows from the top tank to the bottom tank. Tubes are mounted vertically. The cross flow radiator is designed so coolant flows horizontally from one tank to the other. The tubes are mounted horizontally and the tanks are mounted on the sides.

Measuring a radiator:

Three specific measurements are needed to ensure right size and these are; height, width and thickness. No matter what type of radiator? The height measurement is always between the two tanks from header to header or we can say on the length of the tube (reading X). The core width is measured is between the side plates or across the tubes and does not include the side plates (reading Y). The depth is the measurement in thickness of the radiator core depending on how many rows the radiator was built. An easy way to measure thickness is by inserting a wire through the fins until flush with the core. Mark the other end of the wire and measure the wire (reading Z).

FigureD-1


Table D-2

T echnical Specifications MARUTI UDYOG LTD 800 AC BS-II(MB 308)

Body Two Box 4 door Hatchback

Brakes Front Disc Brakes Rear Drum Brakes Dimension & weight Fuel Tank capacity 28 (Litres) Ground Clearance 170 (mm) Kerb weight 665 kg (BS II & BS III) Overall Height 1405 (mm) Overall Length 3335 (mm) Overall Width 1440 (mm) Wheelbase 2175 (mm) Engine Displacement 796 (cc)

No. cylinders / arrangement / Valves/ Cylinder Block Material

3 cylinder, in-line, 6 valves, Cast Iron

Type Water cooled (Water + Ethylene Glycol)SOHC (1C2V)

Performance Max. Power 37 bhp @ 5000 rpm Max. Torque 59 Nm @ 2500 rpm. Steering Min. Turning Radius 4.4 (m) Type Rack & Pinion Suspension Front McPherson strut & coil spring

Rear Coil spring with gas filled shock absorbers

Transmission

Transmission type 4 speed manual, forward and all synchromesh

Tyres & Wheels Tyres 145 / 70 R-12 (Radial)


Figure D-3

Schematic Representation of 3-cylinder inline engine


Car Dimensions Measurement:

Figure D-4


Figure D-5


Figure D-6



Figure D-7

Table D-8


TableD-9


Table D-10


Figure D-11


Figure D-12


Table D-13

Properties of Aluminium:

Melting Point: 933 K

Density (ρ): 2702 kg/m3

Sp. Heat (Cp): 903 J/kg.K

Thermal Conductivity (k): 237 w/m.k

Thermal Diffusivity (α): 97.1×106 m2/s

Coefficient of linear thermal expansion: 2.3×10-6 / 0C

Modulus of elasticity (E): 1×105 N/mm2


TableD-14


Ethylene glycol Properties

General

Name Ethane-1,2-diol

Chemical formula HOCH2CH2OH

Formula weight 62.07 u

Synonyms Ethylene Glycol

IUPAC name: Ethane-1, 2-diol

Phase behavior

Melting point 260.2 K (−12.9 °C)

Boiling point 470.4 K (197.3 °C)

Triple point 256K(-17°C)

Critical point 720K(447°C) 8.2 MPa

∆fusH 9.9 kJ/mol

∆fusS 38.2 J/(mol·K)

∆vapH 65.6 kJ/mol

Solubility Miscible with water

Liquid properties

∆fH0liquid -460 kJ/mol

S0liquid 166.9 J/(mol·K)

Cp 149.5 J/(mol·K)

Density 1.1132 g/cm3


Gas properties

∆fH0gas -394.4 kJ/mol

S0gas 311.8 J/(mol·K)

Cp 78 J/(mol·K)

Safety

Acute effects Nausea,vomiting.CNSparalysis.Kidney damage.

Chronic effects Kidney damage

Flash point 111 °C

Auto ignition temperature 410 °C

Explosive limits 1.8–12.8%

Nylon6/6 [Polyamide 6-6(PA66)]

C12H22O2N2 -

Glass transition temperature: 50oC.

Melting temperature: 255oC.

Amorphous density at 25oC: 1.07 g/cm3.

Crystalline density at 25oC: 1.24 g/cm3.

Molecular weight of repeat unit: 226.32 g/mol.

Decription: Nylon-6,6(PA66) is semicrystalline polyamide commonly used in fiber applications

such as carpeting, clothing, and tire cord. It is also used as an engineering material in

bearings and gears due to its good absoption resistance and self-lubrication properties.


Table D-15

NYLON 66/6

PHYSICAL PROPERTIES

Density 0.039-0.0419 lb/in3

Water Absorption 0-10 % Moisture Absorption at Equilibrium 2.1-4 % Water Absorption at Saturation 0-12 % Moisture Vapor Transmission 356 cc-mil/100 in²-24hr-atm Oxygen Transmission 88.9 cc-mil/100 in²-24hr-atm Environmental Stress Crack Resistance 1000 hour Linear Mold Shrinkage 0.008-0.011 in/in Linear Mold Shrinkage, Transverse 0.01-0.011 in/in Melt Flow 60 g/10 min

MECHANICAL PROPERTIES

Hardness, Rockwell R 76-118 Tensile Strength, Ultimate 4790-11600 psi Tensile Strength, Yield 2180-12300 psi Elongation @ break 5-640 % Elongation @ Yield 5-50 % Tensile Modulus 46.4-537 ksi Flexural Modulus 27.6-508 ksi Flexural Yield Strength 1310-15200 psi Compressive Yield Strength 2470 psi Taber Abrasion, mg/1000 Cycles 10 Shear Strength 8560 psi Izod Impact, Notched 0.562- NB Izod Impact, Notched Low Temp 0.918-3.5 ft-lb/in Charpy Impact, Unnotched 28.6-NB Charpy Impact, Notched Low Temp 1.9 ft-lb/in2

Charpy Impact 1.43-16.7 ft-lb/in2

Coefficient of Friction, Static 0.5-1 Tensile Creep Modulus, 1 hour 145000 psi Tensile Creep Modulus, 1000 hours 129000 psi



ELECTRICAL PROPERTIES

Electrical Resistivity 1E+11-1E+15 ohm-cm Dielectric Constant 3.2-6 Dielectric Constant, Low Frequency 3.7-4.1 Dielectric Strength 457-3050 kV/in Dissipation Factor 0.02-0.3 Dissipatin Factor, Low Frequency 0.01--0.03 Surface Resistance 1E+10-1E+15 ohm Comparative Tracking Index 600 V

THERMAL PROPERTIES

CTE, linear 200 C 36.1-47.2 µ in/in-°F

CTE, linear 20° C Transvers to Flow 50 µ in/in-°F

Melting Point 374-500°F

Maximum Service Temperature, Air 135-311°F

Deflection Temperature at 0.46 MPa 180-435°F

Deflection Temperature at 1.8 MPa 135-194°F

Vicat Softening Point 482°F Flammability, UL94 V-0

Oxygen Index 34-37%

OPTICAL PROPERTIES

Haze 1-4 % Gloss 130-145% Transmission, Visible 80%

PROCESSING PROPERTIES

Processing Temperature 482-536°F Rear Barrel Temperature 482°F Middle Barrel Temperatue 482°F Front Barrel Temperature 500°F Mold Temperature 122°F Drying Temperature 176°F

tis text meant just to take up lots of space at the bottom of the page, so tht if there is only a table or here is not any wide...


References

• Paul W.Gill ,James H. Smith,JR. & Eugene J Ziurys, Fundamentals of INTERNAL COMBUSTION ENGINES,OXFORD & IBH PUBLISHING CO. PVT. LTD.New Delhi

• M.L.Mathur,R.P. Sharma, INTERNAL COMBUSTION ENGINES,DHANPAT

RAI PUBLICATIONS,New Delhi

• Willard W.Pulkrabek,Engineering Fundamentals of the Internal Combustion Engine,Pearson Education,New Delhi

• V GANESAN, INTERNAL COMBUSTION ENGINES,Tata McGraw-Hill

Publication,New Delhi

• Richard F. Armento (Executive Director California Automotive Radiator Association),AUTOMOTIVE COOLING SYSTEM,TRAING AND REFERENCE MANUAL,RESTON Publishing Company,Inc,A Prentice-Hall Company Reston,Virginia

• Wiiliam H. Crouse,Donald L. Anglin,The Auto Book-II Edition, McGraw-Hill

• Wiiliam H. Crouse,Automobile Fuel,Lubricating and Cooling Systems,

McGraw-Hill

• M.J.Nunney,The Automotive Engine,London,Newnes-Butterwords

• J.P.Holman, Heat Transfer, Tata McGraw-Hill Edition,New Delhi

• Yunus A. Cengel,Heat Transfer, Tata McGraw-Hill Edition,New Delhi

• G.F. Hewitt,G.L. Shires,T.R.Bott,Process Heat Transfer,CRC PRESS(Begall House) Boca Rotan Ann Arbor London Tokyo

• S.Kakac, A.E.Bergles, F.Mayinger,Heat Exchangers -THERMAL-

HYDRAULIC FUNDAMENTALS AND DESIGN,Hemisphere Publishing Corporation

• Domkundwar & Domkundwar, HEAT & MASS TRANSFER DATA BOOK,Dhanpat Rai & Co.,Delhi

• Dr. Kirpal Singh,Automobile Engineering Volume 2,Standard Publishers

Distributors,Delhi

• Anthony E.Schwaller,Motor Automobile Mechanics, Delmar publishers Inc.


• Wiiliam H. Crouse,Donald L. Anglin ,Automotive Mechanics, Tata McGraw-

Hill Publication,New Delhi.

• Sham Tickoo, Pro/Engineer for Engineers & Designers, Dreamtech Press, New Delhi.

Websites:

• How stuffworks.com • indiacar.com • Complete Radiators.com • 3d-cam.com • Injectoplast.com • ANSYS.com • azom.com • shyamvenugopal.com • Titan-lite.com

Maruti service manual: Maruti service Centre CSIL (Climate Systems India Limited) SUMMER TRAINING REPORT: Maruti Radiator Manufacturer Injetoplast: Tanks, Fans, Shrouds and plastic automobile equipment manufacturer.

analysis of maruti 800

Documents