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A Reusable Launch Vehicle (RLV)
Akash Bhosale and Abrarahmad Mulla
Launching satellites or humans to space is a costly affair. Since man stepped on moon, it has been the constant
dream of engineers, policymakers and others among the space community to develop and design a vehicle that
can be used for multiple launch missions, like an aircraft, whether military or transport. The only success
achieved so far is the Space Shuttle Program that has been shelved in 2011. The retirement of the Space Shuttle
has left a huge void in the field of space exploration, and even though NASA is following up with the space
capsule Orion, there is a renewed interest in Reusable Launch Vehicles (RLV).
The Indian Space Research Organization (ISRO) announced on January 7th
, 2015, that they will perform a RLV
technology demonstration in March. If successful, this test will be a big achievement for India and ISRO, and
will cement its position as a forerunner in the field of space exploration.
What is a Reusable Launch Vehicle?
A Reusable Launch Vehicle (RLV) is the space analog of an aircraft. Ideally it takes off vertically on the back
of an expendable rocket and then glides back down like an aircraft. During landing phase, an RLV can either
land on a runway or perform a splashdown. Small wings provide maneuverability support during landing.The
main advantage of an RLV is it can be used multiple times, hopefully with low servicing costs. The expendable
rocket that is used for launching the RLV can also be designed to be used multiple times. A successful RLV
would surely cut down mission costs and make space travel more accessible.
Vehicle Technology Demonstrator (RLV-TD) to act as a platform to demonstrate various
technologies like
1) Hypersonic flight,
2) Autonomous landing,
3) Flush air data measurements,
4) Re-entry thermal protection systems, etc.
Indian Perspective on RLV:
ISRO’s RLV Technology Demonstration Programme (RLV-TD) is a plane-like reusable vehicle launched by an
expendable single state solid booster. The mission will end with a splashdown in the Indian Ocean.The rocket
launcher will help it to reach Mach 6, and an altitude of 100 km. After reaching the required height it will
undergo the re-entry phase, glide down and finally splash down in the Bay of Bengal. The vehicle will spend
nearly 5 minutes in its coast phase at the maximum altitude before doing re-entry.The RLV-TD Program is not
just a technology demonstration for India, but a way to prove how much it has progressed in the field of space
exploration. The test is a part of a larger plan to build a fully functional two stage to orbit (TSTO) vehicle.
Currently the annual spending budget of IRO for launching satellites is Rs. 300 cr (48.7M USD). A successful
RLV program would reduce the cost of space missions, making India more competitive in the launcher market.
For now, the test program will expand the technological capabilities of India, enabling it to be a forerunner in
space exploration in near future.The success of the Mars Orbiter Mission at the first attempt has boosted the
hopes of ISRO to send humans to Mars. A highly developed version of RLV for launching humans to
space could demonstrate the technological ability and progress achieved by Indians in the field of space
exploration. The series of experiments that need to be carried out will help in expansion of space technology
and capability of ISRO and India culminating in a fully developed version of RLV used as Two Stages to Orbit
(TSTO) vehicle.
1 BLADELESS FAN AMEY SAPKAL(BE MECH)
In October 2009, James Dyson's consumer electronics company, famous for its
line of vacuum cleaners, introduced a new device to the market called the Dyson
Air Multiplier. The Air Multiplier is a fan with an unusual characteristic: It doesn't
have any visible blades. It appears to be a circular tube mounted on a pedestal. The
shallow tube is only a few inches deep.
Looking at the device, you wouldn't expect to feel a breeze coming from the
mounted circle. There are no moving parts in sight. But if the fan is switched on,
you'll feel air blowing through the tube. How does it work? How can an open circle
push air into a breeze without fan blades?
As you might imagine, there are a few scientific principles at play here. There's
also an electronic element. While the tube doesn't have any blades inside it, the
2 BLADELESS FAN AMEY SAPKAL(BE MECH)
pedestal of the fan contains a brushless electric motor that takes in air and feeds it
into the circular tube. Air flows along the inside of the device until it reaches a slit
inside the tube. This provides the basic airflow that creates the breeze you'd feel if
you stood in front of the fan.
According to Dyson, the breeze generated by the Air Multiplier is more consistent
and steady than one from a standard fan with blades. Since there are no rotating
blades, the breeze from the fan doesn't buffet you with short gusts of air.
How the Dyson Bladeless Fan Works??????
Calling the Dyson Air Multiplier a fan with no blades is perhaps a touch
misleading. There are blades in the fan -- you just can't see them because they're
hidden in the pedestal. A motor rotates nine asymmetrically aligned blades to
pull air into the device. According to Dyson, these blades can pull in up to 5.28
gallons (about 20 liters) of air per second.
The air flows through a channel in the pedestal up to the tube, which is hollow.
The interior of the tube acts like a ramp. Air flows along the ramp, which curves
around and ends in slits in the back of the fan. Then, the air flows along the surface
of the inside of the tube and out toward the front of the fan. But how does the fan
multiply the amount of air coming into the pedestal of the device?
3 BLADELESS FAN AMEY SAPKAL(BE MECH)
It boils down to physics. While it's true that the atmosphere is gaseous, gases obey
the physical laws of fluid dynamics. As air flows through the slits in the tube and
out through the front of the fan, air behind the fan is drawn through the tube as
well. This is called inducement. The flowing air pushed by the motor induces the
air behind the fan to follow.
Air surrounding the edges of the fan will also begin to flow in the direction of the
breeze. This process is called entrainment. Through inducement and entrainment,
Dyson claims the Air Multiplier increases the output of airflow by 15 times the
amount it takes in through the pedestal's motor.
James Dyson demonstrates that there are indeed no visible blades on the Air Multiplier.
CLOUD MANUFACTURING
UJWAL D. ADMUTHE (T.E, A)
AKASH V. BHOSALE (T.E, A) Page 1
CLOUD MANUFACTURING
DEFINITION
Cloud manufacturing is a service-oriented, knowledge-based smart
manufacturing system with high efficiency and low energy consumption. In a
cloud manufacturing system, state-of-the-art technologies such as informatized
manufacturing technology, cloud computing, Internet of Things, semantic Web,
high-performance computing, and cloud manufacturing are integrated. By
extending and shifting existing manufacturing and service systems,
manufacturing resources and capabilities are virtualized and oriented towards
service provision. Cloud manufacturing provides the whole manufacturing
lifecycle with secure, reliable, high quality, and on-demand services at low
prices through networked system. The manufacturing lifecycle includes pre-
manufacturing (argumentation, design, production and sale), manufacturing
(product usage, management and maintenance), and post-manufacturing
(dismantling, scrap, and recycling).
So What Exactly is the Cloud?
“cloud” simply means that your software, data and related infrastructure are
hosted remotely via the Internet. Cloud manufacturing has become so popular
because it lowers costs while scaling seamlessly with your business. Essentially
you’re paying someone else to deal with your IT headaches, including support,
security and maintenance. You only pay for what you need, and you can expand
or change cloud services on the fly — with no capital outlay.
Operation Model and Key Technologies of Cloud Manufacturing A cloud manufacturing system consists of manufacturing resources and
capabilities, manufacturing cloud, and the whole manufacturing lifecycle
applications. It also includes core support (knowledge), two processes (import
and export), and three user types—resource providers, cloud operators and
resource users. Figure 1 illustrates the operational principle of cloud
manufacturing. Manufacturing resources and capabilities are encapsulated as
cloud services. This process is called manufacturing resource "import".
Depending on different manufacturing requirements, cloud services are
combined to form a manufacturing cloud. The cloud provides the whole
manufacturing lifecycle applications with diverse services. This process is
called "export". Knowledge plays a central role in supporting the entire
operating process of cloud manufacturing. It is necessary for intelligent
embedding and virtualized encapsulation during import; it assists functions such
as intelligent search of cloud services; and it facilitates smart cooperation of
cloud services over the whole manufacturing lifecycle. In cloudmanufacturing
system, knowledge-based integration across the whole lifecycle is possible.
CLOUD MANUFACTURING
UJWAL D. ADMUTHE (T.E, A)
AKASH V. BHOSALE (T.E, A) Page 2
A cloud manufacturing application Users send specific requests to the cloud manufacturing platform. This platform
is responsible for the management, operation, and maintenance of
manufacturing clouds and service tasks such as import and export. It analyzes
and divides service requests, and automatically searches the cloud for best-
matched services. By a series of processes including scheduling, optimization
and combination, a solution is generated and then sent back to the client. A user
does not need to communicate directly with every service node, nor find the
specific locations and situations of service nodes. Through the cloud
manufacturing platform, manufacturing resources and capabilities can be used
in the same way as water, gas, electricity, etc.
References
• https://en.wikipedia.org/wiki/Cloud_manufacturing
• https://commons.wikimedia.org
• ftp://ftp.nist.gov/pub/mel/michalos/Publications/2014/JournalPaper/bib/C
loud-Based%20manufacturing%20systems.pdf
NileshsingRajput(Department Of Mechanical Engineering) Page 1
Casting directly from a computer model by
using advanced simulation software
FLOW-3D Cast
INTRODUCTION:
In todays highly competitive world saving in product development cost is very important. For
that purpose new methods to be adopted for manufacturing as well as simulation and
optimization of processes. A patternless casting technique, originally conceived at VTT
Technical Research Centre of Finland andfurther developed at its spin-off company, Simtech
Systems, offers up to 40% savings in product development costs, and upto two months shorter
development times compared to conventional techniques. Savings of this order can be very
valuable on today's highly competitive markets. Casting simulation is commonly used for
designing of casting systems. However, most of the software are today old fashioned and
predicting just shrinkage porosity. Flow Science, VTT and Simtech have developed new
software called FLOW-3D Cast , which can simulate surface defects, air entrainment, filters, core
gas problems and even a cavitation.
Simtech’spatternless casting technology allows developers to completely by-pass one of the
main stages in traditional casting the making of casting patterns. The advantages of this approach
are best appreciated when several prototypes are required for a short production run, or when
products vary slightly in detail. The technology achieves this by using a robot to prepare a mold
directly from a CAD model, or from an existing spare part or artist’s model. Using the relevant
control data, the operator directs the robot to machine the shape into a mold made of hardened
sand, which is then cast in the normal way.
ConiferRob - Precision control:
Simtech Systems’ ConiferRob® precision software fills the processgap between machining path
generation systems, such as CAD systems,and industrial robots running machining
programs.ConiferRob ® can convert and move a machining program in *.apt format into a robot
for execution both quickly and safely. In addition to optimum accuracy, the positioning of work
pieces can also be easily designed and reviewed with the help of ConiferRob®– as its
reachability analysis options allow potential positioning problems to be identified and ensure that
the final positioning selected will work in practice.The technology can also be applied to other
areas ofmanufacturing that work with complicated shapes and extreme dimensions in materials
other than metal, such as plastic injection molding. Occupational safety is also improved, as
mold production takes place in a closed robot cell, which prevents the migration of potentially
hazardous particles into employees’ respiratory tract sand dust into ambient foundry air.
NileshsingRajput(Department Of Mechanical Engineering) Page 2
Fig 1.ConiferRobprogramme enables user to do robotic
offline machining with automatically optimized paths
together with very high precision collision detection.
FLOW-3D Cast software for foundries: FLOW-3D Cast is divided into different solver modules with increasing capabilities according to
the process. It also offers accessory modules for e.g. materials data and designing.FLOW-3D
Cast ® uses 3D CFD (computational fluid dynamic) simulation software as a calculation engine.
The program is based on the fundamental laws of mass, momentum and energy conservation. 3D
CFD has been supplied with a large variety of auxiliary physical models.
• Innovative Aspects: Very effective software in turbulence modeling oftwo phase flows - predict the sharp interface
between themolten metal and air during the filling. This is veryessential when the flow fronts are
breaking and smalldroplets are emerging into die cavity.Easy to use interface allowing operators
to use itwithout extensive training.Possibility to include allnecessary tools for casting
simulations.
• Main Advantages : Casting simulation using 3D CFD (computationalfluid dynamic) algorithms is becoming an
important part ofthe casting process in the modern foundry, allowing timeoptimization and cost
reduction by simulating what willhappen during the actual casting of molten metal at designtime,
experimenting alternative solutions without the needto set up trial and error.
REFERENCES:
[1] Sirviö, M. and Martikainen, H. “Simultaneous engineeringbetween workshops and
foundries” .Int. Conf. on BestPractices in the Production, Processing and Thermal
Treatment of Castings. Singapore, 10 - 12 Oct. 1995.
[2] Sirviö, M .andLouvo, A. “Use of simulated porosity foravoidance of casting defects”.
International GIFACongress Metal Casting '94 (GIFA '94). Dusseldorf, 18 June 1994
Functionally Graded Materials 2015-16
1 Annasaheb Dange College of Engineering and Technology, Ashta.
Functionally Graded Materials
SHIVRAJ NAGESH GURAV
shivrajgurav796@yahoo.in
Student, B.E. Mechanical Engineering, A.D.C.E.T, Ashta, Dist. Sangli, MS.
I. INTRODUCTION
Pure metals are of little use in
engineering applications because of the demand
of conflicting property requirement. For
example, an application may require a material
that is hard as well as ductile, there is no such
material existing in nature. To solve this
problem, combination (in molten state) of one
metal with other metals or non-metals is used.
This combination of materials in the molten state
is termed alloying (recently referred to as
conventional alloying) that gives a property that
is different from the parent materials. Bronze,
alloy of copper and tin, was the first alloy that
appears in human history. Bronze really
impacted the world at that time, it was a
landmark in human achievement and it is tagged
the ‘Bronze Age’ in about 4000 BC. Since then,
man has been experimenting with one form of
alloy or the other with the sole reason of
improving properties of material. There is limit
to which a material can be dissolved in a solution
of another material because of thermodynamic
equilibrium limit. When more quantity of the
alloying material is desired, then the traditional
alloying cannot be used. Another limitation of
conventional alloying is when alloying two
dissimilar materials with wide apart melting
temperatures; it becomes prohibitive to combine
these materials through this process. Powdered
Metallurgy (PM) is another method of producing
part that cannot be produced through the
conventional alloying, as alloys are produced in
powdered form and some of the problems
associated with the conventional alloying are
overcome. Despite the excellent characteristics
of powdered metallurgy, there exist some
limitations, which include: intricate shapes and
features that cannot be produced using PM; the
parts are porous and have poor strength.
ABSTRACT: In materials science functionally graded material (FGM) may be spotted by the variation in
composition and structure gradually over volume, resulting in corresponding changes in the properties of the
material. The overall properties of FMG are unique and different from any of the individual material that forms it.
There is a wide range of applications for FGM and it is expected to increase as the cost of material processing and
fabrication processes are reduced by improving these processes. In this article, an overview of fabrication processes,
area of application, some recent research studies and the need to focus more research effort on improving the most
promising FGM fabrication method (solid freeform SFF) is presented. Improving the performance of SFF processes
and extensive studies on material characterization on components produced will go a long way in bringing down the
manufacturing cost of FGM and increase productivity in this regard.
Functionally Graded Materials 2015-16
2 Annasaheb Dange College of Engineering and Technology, Ashta.
Although these limitations are of advantage to
some applications (e.g. filter and non structural
applications) but are detrimental to others.
Another method of producing materials with
combination of properties is by combining
materials in solid state, which is referred to as
composite material. Composite material are a
class of advanced material, made up of one or
more materials combined in solid states with
distinct physical and chemical properties.
Composite material offers an excellent
combination of properties which are different
from the individual parent materials and are also
lighter in weight. Wood is a composite material
from nature which consists of cellulose in a
matrix of lignin. Composite materials will fail
under extreme working conditions through a
process called delimitation (separation of fibers
from the matrix). This can happen for example,
in high temperature application where two
metals with different coefficient of expansion are
used. To solve this problem, researchers in Japan
in the mid 1980s, confronted with this challenge
in an hypersonic space plane project requiring a
thermal barrier (with outside temperature of
2000K and inside temperature of 1000K across
less than 10 mm thickness), came up with a
novel material called Functionally Graded
Material (FGM). Functionally Graded Material
(FGM), a revolutionary material, belongs to a
class of advanced materials with varying
properties over a changing dimension.
Functionally graded materials occur in nature as
bones, teeth etc., nature designed this materials
to meet their expected service requirements. This
idea is emulated from nature to solve engineering
problem the same way artificial neural network
is used to emulate human brain.
II. PROCESSING TECHNIQUES OF
FUNCTIONALLY
GRADED MATERIALS (FGM)
Thin functionally graded materials are usually in
the form of surface coatings, there are a wide
range of surface deposition processes to choose
from depending on the service requirement from
the process.
A. Vapor Deposition Technique
There are different types of vapor
deposition techniques, they include: sputter
deposition, Chemical Vapor Deposition (CVD)
and Physical Vapor Deposition (PVD). These
vapor deposition methods are used to deposit
functionally graded surface coatings and they
give excellent microstructure, but they can only
be used for depositing thin surface coating. They
are energy intensive and produce poisonous
gases as their byproducts. Other methods used in
producing functionally graded coating include:
plasma spraying, electro deposition, electro-
phoretic, Ion Beam Assisted Deposition (IBAD),
Self Propagating High-temperature Synthesis
(SHS), etc. All the above mentioned processes
cannot be used to produce bulk FGM because
they are generally slow and energy intensive,
therefore they are uneconomical to be used in
producing bulk FGM.:
B. Powder Metallurgy (PM)
Powder metallurgy (PM) technique is used to
produce functionally graded material through
three basic steps namely: weighing and mixing
of powder according to the pre designed spatial
Functionally Graded Materials 2015-16
3 Annasaheb Dange College of Engineering and Technology, Ashta.
distribution as dictated by the functional
requirement, stacking and ramming of the
premixed-powders, and finally sintering. PM
technique gives rise to a stepwise structure. If
continuous structure is desired, then centrifugal
method is used.
C. Centrifugal Method
Centrifugal method is similar to centrifugal
casting where the force of gravity is used
through spinning of the mould to form bulk
functionally graded material. The graded
material is produced in this way because of the
difference in material densities and the spinning
of the mould. There are other similar processes
like centrifugal method in the literature (e.g.
gravity method, etc.). Although continuous
grading can be achieved using centrifugal
method but only cylindrical shapes can be
formed. Another problem of centrifugal method
is that there is limit to which type of gradient can
be produced because the gradient is formed
through natural process (centrifugal force and
density difference). To solve these problems,
researchers are using alternative manufacturing
method known as solid freeform.
D. Solid Freeform (SFF) Fabrication Method
Solid freeform is an additive manufacturing
process that offers lots of advantages that
include: higher speed of production, less energy
intensive, maximum material utilization, ability
to produce complex shapes and design freedom
as parts are produced directly from CAD (e.g.
AutoCAD) data. SFF involves five basic steps:
generation of CAD data from the software like
AutoCAD, Solid edge etc, conversion of the
CAD data to Standard Triangulation Language
(STL) file, slicing of the STL into two
dimensional cross-section profiles, building of
the component layer by layer, and lastly removal
and finishing.
III. FUTURE RESEARCH DIRECTION
Functionally graded material is an
excellent advanced material that will
revolutionize the manufacturing world in the
21st century. Cost is a major problem, with
substantial part of the cost expended on powder
processing and fabrication method. Solid
freeform fabrication technique offers a greater
advantage for producing FGM. More research
needs to be conducted on improving the
performance of SFF processes through extensive
characterization of functionally graded material
in other to generate a comprehensive database
and to develop a predictive model for proper
process control. Further work should also be
done to improve the process control through
development of more powerful feedback control
for overall FMG fabrication process
improvement (i.e. full automation). This will
improve the overall performance of the process,
bring down the cost of FGM and improve
reliability of the fabrication process.
References:
[1] Bever MB, Duwez PE (1972) Gradients in
composite materials. Mater Sci Eng 10(1):1:8
[2] Shen M, Bever MB (1972) Gradients in
polymeric materials. J Mater Sci 7(7):741-746
[3] Lee WY, Bae YW, More KL (1995)
Synthesis of functionally graded metal-ceramic
microstructures by chemical vapor deposition. J
Mater Res 10(12):3000-3002
DEVENDRA S. PATIL (BE Mechanical)
Honda’s new eight-speed DCT
Dual-clutch transmission-essentially
two parallel gearboxes that hand off
power from one to the other, and do
it more efficiently and quicker than
either planetary automatics or
conventional manual transmission-
seem like a dream technology for
engineers seeking both performance
and fuel economy.
But computer management of
their clutches is tricky, and drivers
are regular to the silky launch
provided by a torque-equipped
planetary automatic or frequently
disappointed by the driving
dynamics of DCT’s. The cars can
lurch when trying to move at
parking lot speed, and a DCT can
make inch-perfect parallel parking
frustrating.
Honda has traditionally build
its own automatic transmission
(uniquely without planetary gear
uses a torque converter
set), a strategy that has led to its
transmissions sometimes falling
behind industry fashion. In the case
of Acura TSX, that meant only five
speeds at a time when six is standard
and nine-speed automatics are
available.
The 2015 Acura TLX replaces
the TSX and the more on the TL,
and offers a ZF-sourced nine-speed
automatic transmission with the
optional 3.5-L V6. The base car
pairs its 2.4-L l4 with a Honda-
developed eight-speed DCT, which
features the novel twist of a torque
converter in place of a clutch. Honda
claims it’s the first production DCT
so equipped.
This gives the DCT-equipped
TLX the smooth low-speed driving
dynamics of a traditional automatic
transmission with a gearbox that is
more efficient, according to Chris
Kipfer, the Assistant Large Project
Manager responsible for drivetrain.
Honda’s product planners and
engineers interviewed drivers of car
equipped with DCTs, and “the main
thing they talked about was how
unrefined and unsporting they are,”
said Kipfer. “The main issue is the
low-speed launch.”
DEVENDRA S. PATIL (BE Mechanical)
Incorporating a torque
converter into the unit not only
provides some internal benefits that
helps deliver the low-speed
refinement most drivers seek but its
inherent torque multiplication
boosts-off-the-line acceleration. In
fact, the TLX 2.4-L car accelerates
to 60mph 1.5s faster than the TSX
did, thanks in large part to the use of
a torque converter, he noted.
The torque converter, supplied
by Cardington Yutaka Technologies,
Inc., is more expensive than a clutch
for the same application. But DCT
clutches demand use of the more
costly dual-mass flywheel, so the
torque converter solution is no more
expensive overall, according to
Kipfer.
The eight-speed’s additional
ratios permit a much wider ratio
spread than the old five-speed
automatic, contributing to the
speedier acceleration and improved
fuel efficiency. Where the old five-
speed’s lowest gear was an 11:1
ratio, the TLX’s DCT launches with
a 14:1 ratio.
The DCT’s first seven ratios
are all lower than those in the old
automatic, while the eight gear’s
2.212:1 ratio is higher than the
2.512:1 of the old one, for better
highway fuel efficiency. This wider
ratio spread contributes, along with
changes to the engine, to the TLX’s
four-cylinder scoring 2 mpg higher
on the U.S. EPA’s city driving cycle
and 4 mpg higher on the highway
test.
The engineer team’s biggest
task in developing the DCT was to
optimize the transmission’s ability to
change gears quickly, without
hammering the car’s occupants with
hard upshifts, said Kipfer.
“It was getting the feeling just
right and making sure they are quick
shifts without shocks,” he explained.
The Honda-build DCT upshifts 33%
faster than the five-speed automatic
used in the outgoing TSX.
References:
-Technology Report, Automotive
Engineering, SAE sections,
September 2, 2014.
Magazine.sae.org/auto.
nanofluids in heat transfer 2015
Sonali Kadam T.E.A Page 1
Cooling is one of the most
important technical challenge facing
by diverse industries, including
microelectronics, transportation,
solid- state lighting, and
manufacturing. Technological
developments such as microelectronic
devices with smaller features and
faster operating speeds, higher power
engines, and brighter optical devices
driving increased thermal loads
,required advances in cooling. The
conventional method for increasing
heat transfer rate is to increase the
area available for exchanging heat
with a heat transfer fluid . however
this approach requires an undesirable
increase in thermal management
system’s size. There is therefore
urgent need for new and innovative
coolants with improved performance.
The novel concept of ‘nanofluids’-
Nanofluids are dilute liquid
suspensions of nanoparticles with at
least one of their principal dimensions
smaller than 100 nm
Flowing Properties of nanoparticles
which make them suitable for heat
transfer:
1.higher heat conduction : the large
surface area of nanoparticles allows
for more heat transfer.
2.stabilty: because the particles are
small, they weigh less ,and chances of
sedimentation are also less. This
overcome the drawback of
suspensions, setlling of particles.
3.microchannel cooling without
clogging: they are also ideal for
microchannel applications where
high heat rates are encountered.
4. reduced chances of erosion : as
they are very small , momentum they
can import to soli wall is very smaller.
This reduces the chances of erosoin of
components.
5. small concentrations and
Newtonian behavior : large
enhancement in thermal conductivity
is achieved by the small concentration
of paticles, the rise in viscosity is
nominal; hence, pressure drop was
increased marginally.
nanofluids in heat transfer 2015
Sonali Kadam T.E.A Page 2
2. Preparation of nanofluids
The nanofluid does not simply
refer to a liquid+solid mixture. Some
special requirements are necessary,
such as even suspension, stable
suspension, durable suspension, low
agglomeration of particles, no
chemical change of the fluid. In
general, these are e€ective methods
used for preparation of suspensions:
(1) to change the pH value of
suspensions;
(2) to use surface activators and/or
dispersants;
(3) to use ultrasonic vibration.
All these techniques aim at changing
the surface properties of suspended
particles and suppressing formation of
particles cluster in order to obtain
stabile suspensions. The common
activators and dispersants are thiols,
oleic acid, laurate salts. While
preparing the suspensions, diferent
types and percentages of activators or
dispersants have been tried and tested.
After the suspension has been
vibrated in a ultrasonic vibrator, the
stabile suspension can last more than
30 h in the stationary state.
in recent studies it is found that heat
transfer coefficients of magnetite
nanofluids were increased up to
300%when local magnetic field was
applied. In typical nanofluids, the
nanoparticals are uniformly dispersed.
In solution of magnetic nanofluids,
however, the particles can be
controlled by using external magnetic
field, which enhance their thermal
conductivity.
It was reported by many of the
researchers that the increase in the
effective thermal conductivity and
huge chaotic movement of
nanoparticles with increasing particle
concentration is mainly responsible
for heat transfer enhancement.
However, there exists aplenty
of controversy and inconsistency
among the reported results. The
outcome of all heat transfer works
using nanofluids showed that our
current understanding on nanofluids is
still quite limited. There are a number
of challenges facing the nanofluids
community ranging from formulation,
practical application to mechanism
understanding. Engineering suitable
nanofluids with controlled particle
size and morphology for heat transfer
applications is still a big challenge.
REFERENCES:
[1] Sarit k. Das, Nandy
Putra,Wailfried Roetzel.Pool Boiling
Characterstics Of Nanofluides.
[2]Stefen U.S.Choi,
J.A.Estaman Enhancing thermal
conductivity of fluids with
nanoparticles
[3]Yimin Xuan, Wilried
Roetzel, Concepion of heat transfer
correlation for heat transfer.
PRATIK DESHMUKH T.E. A ADCET
1
THERMOELECTRIC REFRIGERATION SYSTEM
Abstract
Refrigeration is a process in which work is done to move heat from one location to
another. The work of heat transport is traditionally driven by mechanical work, but can also be
driven by magnetism, laser or other means. A thermoelectric refrigerator in the same way is a
refrigerator that uses the Peltier effect to create a heat flux between the junction of two different
types of materials. TEC also called as Peltier cooler is a solid state heat pump which transfers
heat from one side of the device to the other side against the temperature gradient (from cold to
hot), with consumption of electrical energy. However it is not used conventionally because of its
low efficiency.
Introduction
In 1821, Thomas Seeback discovered that a continuously flowing current is created when
two wires of different materials are joined together and heated at one end. This idea is known as
the seeback effect. The seeback effect has two main applications including temperature
measurement and power generation. Thirteen years later Jean Charles Athanase reversed the
flow of electrons in seeback.s circuit to create refrigeration. This effect is known as the Peltier
Effect. This idea forms the basis for the Thermoelectric refrigerator.Scottish scientist
WilliamThomson (later Lord Kelvin) discovered in 1854 that if a temperature difference exists
between any two points of a current carrying conductor, heat is either evolved or absorbed
depending upon the material.6 If such a circuit absorbs heat, then heat may be evolved if the
direction of the current or of the temperature gradient is reversed. The Peltier effect is a
temperature difference created by applying a voltage between two electrodes connected to a
sample of semiconductor material. This phenomenon can be useful when it is necessary to
transfer heat from one medium to another on a small scale. The Peltier effect is one of three
types of thermoelectric effect; the other two are the seeback effect and the Thomson effect. In a
Peltier-effect device, the electrodes are typically made of a metal with excellent electrical
conductivity. The semiconductor material between the electrodes creates two junctions between
dissimilar materials, which, in turn, creates a pair of thermocouple voltage is applied to the
electrodes to force electrical current through the semiconductor, thermal energy flows in the
direction of the charge carriers. In its simplest form, this may be done with a single
semiconductor 'pellet' which is soldered to electrically-conductive material on each end (usually
plated copper). In this 'stripped-down' configuration, the second dissimilar material required for
the Peltier effect, is actually the copper connection paths to the power supply. It is important to
note that the heat will be moved (or 'pumped') in the direction of charge carrier flow throughout
the circuit— actually, it is the charge carriers that transfer the heat. But in order to pump
appreciable amount of heat, we need to interconnect such semiconductor electrically and
thermally parallel. Moreover it needs costly power supply arrangement to supply high current
requirement for parallel arrangement of semiconductor. So semiconductor can be arranged
electrically in series but thermally parallel which further increases the possibility of short
circuiting and reduces the reliability of system. The best optimized way to connect the
semiconductor is in the form of pn junctions which overcome the above mentioned problems.
PRATIK DESHMUKH T.E. A ADCET
2
Circuit diagram
REFERENCES
� WIKIPEDIA
� www.sjtuirc.sjtu.edu.cn/jpkc/ziyuan/zhil3.pdf
1
AKSHAY DHANAWADE
T.E. A
ADCET, ASHTA
Virtual Manufacturing
The research area “Virtual Manufacturing” can be defined as an integrated manufacturing
environment which can enhance one or several levels of decision and control in
manufacturing process. Several domains can be addressed: Product and Process Design,
Process and Production Planning, Machine Tool, Robot and Manufacturing System. As
automation technologies such as CAD/CAM have substantially shortened the time required to
design products, Virtual Manufacturing will have a similar effect on the manufacturing phase
thanks to the modelling, simulation and optimisation of the product and the processes
involved in its fabrication.
Manufacturing is an indispensable part of the economy and is the central activity that
encompasses product, process, resources and plant. Nowadays products are more and more
complex, processes are highly-sophisticated and use micro-technology and the market demand
evolves rapidly so that we need a flexible and agile production
In this complex and evolutive environment, industrialists must know about their processes
before trying them in order to get it right the first time. To achieve this goal, the use of a
virtual manufacturing environment will provide a computer-based environment to simulate
individual manufacturing processes and the total manufacturing enterprise. Virtual
Manufacturing systems enable early optimization of cost, quality and time drivers, achieve
integrated product, process and resource design and finally achieve early consideration of
producibility and affordability.
Virtual manufacturing will contribute to the following benefits:
1. Quality: Design For Manufacturing and higher quality of the tools and work instructions
available to support production.
2. Shorter cycle time: increase the ability to go directly into production without false starts.
3. Producibility: Optimise the design of the manufacturing system in coordination with the
product design; first article production that is trouble-free, high quality, involves no reworks
and meets requirements.
4. Flexibility: Execute product changeovers rapidly, mix production of different products,
return to producing previously shelved products.
5. Responsiveness: respond to customer about the impact of various funding profiles and
delivery schedule with improved accuracy and timeless.
6. Customer relations: improved relations through the increased participation of the customer
in the Integrated Product Process Development process.
2
AKSHAY DHANAWADE
T.E. A
ADCET, ASHTA
CONCLUSION
As a conclusion of this paper, we can say that we have now reached a point where everyone
can use VM. It appears that VM will stimulate the need to design both for manufacturability
and manufacturing efficiency. Nowadays, even if there is a lot of work to do, all the pieces are
in place for virtual Manufacturing to become a standard tool for the design to manufacturing
process: computer technology is widely used and accepted, the concept of virtual prototyping
is widely accepted, companies need faster solutions for cost / time saving, for more accurate
simulations, leading companies are already demonstrating then successful use of virtual
manufacturing techniques. Nevertheless, we have to note that there are still some drawbacks
to overcome for a complete integration of VM techniques : data integrity, training, system
integration.
REFERENCES
1. Wikipedia – Virtual Manufacturing
2. www.arxiv.org
1
GOPAL GAWALI ADCET , ASHTAT.E. A
New Wind Turbine Generates Electricity Without Rotating Blades
A Spanish company called Vortex Bladeless has produced a wind turbine that takes advantage of
the vortices produced when wind moves around an obstacle.This new wind turbine wobbles
elegantly in the wind, generating electricity without rotating blades.
“It looks like asparagus,” says David Suriol, one of the founders.If you put any object in the path of
the wind, it will create an undulating vortex behind the barrier. This is a problem that has plagued
engineers for years: bridges have fallen due to wind eddies.
Vortex Bladeless engineers have designed their turbine to take advantage of this vortex. The thin,
cone-shaped turbine is made of carbon fiber and fiberglass with the motor at the bottom instead of
the top (like traditional turbines) to improve sturdiness. The design ensures that the wind's vortex
spins synchronously along the entire cone. There is also a ring of magnets at the base of the cone
that give the rotations a boost regardless of wind speed.
There are many advantages to the new Vortex design=It is cheaper to manufacture than current
pinwheel turbines. Maintenance prices are also lower because there is no friction from
mechanically moving parts, which reduces the need for oiling and bolt replacement. It is
completely silent and birds can fly around them safely.
2
GOPAL GAWALI ADCET , ASHTAT.E. A
The Vortex device has been computationally modeled, tested in a wind tunnel, and there are
prototypes out in the open, but details on tests carried out by the company or independent labs are
currently scant. It is also not the first wind turbine to take advantage of oscillatory technology.
Researchers in the '80s found that the swirling oscillations were too random for reliable power
generation, and the speed of oscillations put a lot of stress on the structure and caused it to break
down unexpectedly.
The Vortex has the same goals as conventional wind turbines: To turn breezes into kinetic energy
that can be used as electricity. Vortex’s lightweight cylinder design has no gears or bearings. The
company has received $1 million in private capital and government funding in Spain and is seeking
another $5 million in venture capital funding. Yáñez says the company plans to release a four-
kilowatt system in 2016 and a much larger one-megawatt device around 2018.
Instead of capturing energy via the circular motion of a propeller, the Vortex takes advantage of
what’s known as vorticity, an aerodynamic effect that produces a pattern of spinning vortices.
Vorticity has long been considered the enemy of architects and engineers, who actively try to
design their way around these whirlpools of wind.
In its current prototype, the elongated cone is made from a composite of fiberglass and carbon
fiber, which allows the mast to vibrate as much as possible. At the base of the cone are two rings of
repelling magnets, which act as a sort of nonelectrical motor. When the cone oscillates one way,
the repelling magnets pull it in the other direction, like a slight nudge to boost the mast’s
movement regardless of wind speed. This kinetic energy is then converted into electricity via an
alternator that multiplies the frequency of the mast’s oscillation to improve the energy-gathering
efficiency.
3
GOPAL GAWALI ADCET , ASHTAT.E. A
Its makers boast the fact that there are no gears, bolts, or mechanically moving parts, which they
say makes the Vortex cheaper to manufacture and maintain. The founders claim their Vortex Mini,
which stands at around 41 feet tall, can capture up to 40 percent of the wind’s power during ideal
conditions. Based on field testing, the Mini ultimately captures 30 percent less than conventional
wind turbines, but that shortcoming is compensated by the fact that you can put double the Vortex
turbines into the same space as a propeller turbine.
REFERENCES
1. WIKIPEDIA
2. www.arising.com
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