thermofluid lab 2-part a

8/18/2019 Thermofluid Lab 2-Part A

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Thermal flu ids Lab-MEC 554/ Rev. 01-2016

1

UNIVERSITI TEKNOLOGI MARA

FACULTY OF

MECHANICAL

ENGINEERING

________________________________________________________________________

Program : Bachelor Of Engineering ( Hons ) Mechanical

Course : Thermalfluids Lab II

Code : MEC 554

________________________________________________________________________

TURBOMACHINARY

TITLE : Compressible flow in converging‐diverging nozzle

1.

OBJECTIVE

To study the pressure‐mass flow rate characteristic for convergent‐divergent duct.

To demonstrate the phenomena of choking.

2. THEORY


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Thermalf luids Lab-MEC 554/ Rev. 01-2016

4

3. EQUIPMENT

The experiment

apparatus

consists

of

a compressible

flow

bench

equip

with

digital

pressure

sensors.

4. Experiment guidelines

Follow the instructions explain by the instructor regarding how to operate the experiment apparatus.

Before starting the experiment, make sure that there is no blockage or object around the convergent‐

divergent nozzle that will interfere with the air flow into the nozzle. Connect the three pressure tap to the

appropriate pressure sensors. Start the experiment from zero velocity and then increase the air velocity

through the nozzle at a constant increment step (eg. 200 rpm) until reaching the maximum air velocity.

Make sure that you record the 3 pressure reading at the nozzle opening, throat and exit for each air velocity

step. Repeat the experiment by decreasing the air velocity from maximum until zero velocity. The air

velocity can be adjusted by changing the rpm of the air blower.

(Experimental parameters can be adjusted according to the conditions and available apparatus at the

time the experiment is conducted.)

5. Data

1.

Calculate the mass flow rate values and the remaining parameters required using the formula

given.

2. Plots the following graphs:

a. vs (P0 – P2) b. vs P2 c.

vs (P0 – P3)

d. vs P3 e. (P0 – P2) vs (P0 – P3)

3.

Comment and analyze the graphs. Compared the maximum values for and the minimum for P2/P0 from the trial with the theoretical values.


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Experiment ID: Date:

Ambient air temperature : Air density:

Atmospheric pressure : Air specific heat ratio:

Convergent‐divergent nozzle specifications:

No.

reading RPM P1 P2 P3 (P0 ‐ P1) (P0 – P2) (P0 – P3) 2 1 [krpm] [kg/s]


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UNIVERSITI

TEKNOLOGI

MARA

FACULTY

OF

MECHANICAL

ENGINEERING ________________________________________________________________________

Program

:

Bachelor

Of

Engineering

(

Hons

)

Mechanical

Course : Thermalfluids Lab II

Code

:

MEC

554

________________________________________________________________________

TURBOMACHINARY

TITLE

:

Performance

of

Pump

1.

OBJECTIVE

To obtain the performance characteristics for a variable speed centrifugal pump operating at 3 different

impeller

speeds.

The

pump

performance

characteristics

that

will

be

study

are

pressure

jump,

power

requirement, flow rate influence and pump speed influence.

2. THEORY


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3. EQUIPMENT

The experiment apparatus consists of a water flow bench and centrifugal pump rigged with sensors to

measures water pressure, flow‐rate, pump speed, pump torque and electric power consumed by the pump.


Follow the instructions explain by the instructor regarding how to operate the experiment apparatus.

Set the bench to only allow the water to flow through only one centrifugal pump. Power on the correct

pump. Allow the system to reach a steady flow condition before recording the pressures, flow rate, pump

speed, pump torque and pump power. The speed of the pump is control by rotating the pump speed control

dial on the control panel. To collect data for 3 different pump speeds, set the speed control dial to 100%,

75% and 50%.

For every pump speed, collect at least 5 data points based on variable flow‐rate. The flow‐rate can be

adjusted using the water flow control valve situated at the highest point of the bench. The flow meter can

be used as a guidance on setting the amount of water flow passing through the pump.

(Experimental parameters can be adjusted according to the conditions and available apparatus at the

time the experiment is conducted.)

5. Data

1. Record the performance characteristic values in a table. Other performance characteristic that can

not be gained directly can be calculated using the formula given in the theory section. (Be careful

on the parameters unit.)

2. Plot the performance graph (Please refer to the graph shown in the theory section). The

performance curves that are of interest are power curve, efficiency curve and pump head curve.

3.

Analyze and discuss the plots.


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Pump Speed, N: rpm

rad/s

Water temperature :

Water density :

No. Electric

motor Pump Input Pump output

Efficiency,

ηPower,

Pm

Torque,

Tshaft

Shaft

Power,

Wshaft

Volume

flow

rate, Q

Inlet pressure,

P1

Discharge

pressure, P2

Water

head,

hp

Output

power,

Pf

[kW] [Nm] [kW] % % [m] [kW] [100%]

1

2

3

4

5


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Pump Speed, N: rpm

rad/s

Water temperature :

Water density :

No. Electric


Efficiency,

ηPower,

Pm

Torque,

Tshaft

Shaft

Power,

Wshaft

Volume

flow

rate, Q

Inlet pressure,

P1

Discharge

pressure, P2

Water

head,

hp

Output

power,

Pf

[kW] [Nm] [kW] % % [m] [kW] [100%]

1

2

3

4

5


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Pump Speed, N: rpm

rad/s

Water temperature :

Water density :

No. Electric


Efficiency,

ηPower,

Pm

Torque,

Tshaft

Shaft

Power,

Wshaft

Volume

flow

rate, Q

Inlet pressure,

P1

Discharge

pressure, P2

Water

head,

hp

Output

power,

Pf

[kW] [Nm] [kW] % % [m] [kW] [100%]

1

2

3

4

5


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Thermalf luids Lab-MEC 554/ LS 5/ Rev. 01-2016

1

UNIVERSITI TEKNOLOGI MARA

FACULTY OF MECHANICAL ENGINEERING ________________________________________________________________________

Program : Bachelor Of Engineering ( Hons ) MechanicalCourse : Thermalfluids Lab IICode : MEC 554

HEAT TRANSFER LABORATORY SHEET

TITLE : HEAT CONDUCTION SIMPLE BAR

1. OBJECTIVE

Investigate Fourier’s law for linear conduction of heat along a simple bar.

2. THEORY

If a plane wall of thickness (x) and area ( A) and thermal

conductivity (k) supports a temperature difference (T) then theheat transfer rate by conduction is given by the equation:

dx

dT Ak Q

Assuming a constant thermal conductivity throughout thematerial and a linear temperature distribution, this is:

x

T Ak Q

3. EQUIPMENT

The equipment is shown in the figure below.


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4. Experiment Guideline

Select an intermediate position for the heater power control (e.g. 10 W) and allow sufficient time fora steady state to be achieved before recording the temperature (T) at all 9 sensor points (T1 to T9)

and the input power reading on the wattmeter (Q ). Remember to measure the distance between

each temperature sensors. This procedure should be repeated for other input powers (e.g. 20 Wand 30W) up to the maximum setting of the control. After each change, sufficient time must beallowed to achieve steady conditions.

5. DATA

HEATER SAMPLE REGION COOLER

x (mm) 0 10 20 30 40 50 60 70 80

x (m) 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Test

#

Q (W)

T1

(°C)

T2

(°C)

T3

(°C)

T4

(°C)

T5

(°C)

T6

(°C)

T7

(°C)

T8

(°C)

T9

(°C)

A

B

C

1. Plot the temperature profile along the entire length. This should reveal three distinct sections ofstraight lines (corresponding to the heater, brass sample, and cooler) having a slope of

approximately T/x.2. Convert the measured temperatures to degrees Kelvin by the following formula:

15.273

C T K T

3. Calculate the cross-sectional area (A) of the circular cylinder by using the equation:

2

4d A

4. The brass sample region is the region of interest. Ignore all other temperature measurementsexcept T4, T5, and T6 and calculate the thermal conductivity of the brass. This is the slope of thestraight line in the brass sample region alone (plotted in 1), given by the equation:

K m

W units

T

x

A

Qk

5. Find published values of brass in books or on the Internet. Compare the value you obtainedwith these values. Which type of brass does your results best compare with (e.g. yellow brass,red brass etc.)? Discuss any source of error in your measured results. Students shouldcomment on how changing the average temperature affects the thermal conductivity.


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Experiment ID:

HEATER SAMPLE REGION COOLER

x (mm)

x (m)

Test

#

Q (W)

T1

(°C)

T2

(°C)

T3

(°C)

T4

(°C)

T5

(°C)

T6

(°C)

T7

(°C)

T8

(°C)

T9

(°C)


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Thermalfluids Lab-MEC 554/ LS 4/ Rev. 01-2016

2

3. EQUIPMENT

Control rectangular heated surfaces will be used to study heat transfer through forced convection.The surfaces are shown in the figure below. The finned surface consists of 9 fins that are each 0.1m high and 0.068 m wide. The pinned surface consists of 17 pins that each have a diameter of0.013 m and are 0.068 m long. (Make sure that you observed and take measurement of the surfacegeometry when you performed the experiment to confirmed the actual dimensions.)


Place the heat exchanger into the test duct and record the ambient temperature (T ). Set the heaterpower control to 75 W. Allow the temperature to rise to 80°C then adjust the heater power control to20 W. This will prepare the heat exchanger for the experimental condition needed.To collect the heat exchanger surface temperature reading, start the stopwatch, wait 5 minute andrecord surface temperature (Ts).Repeat the steps above to obtained data for other conditions (eg. air velocity 0 m/s, 1 m/s, 2m/s….). To introduce air flow in the duct, turn the fan speed control to start the fan. Adjust the fanspeed control to give the desired air velocity. The air velocity can be measure using a thermalanemometer.

The experiment can be repeated for different type of heat exchanger.

(Experimental parameters can be adjusted according to the conditions and available apparatus at the time

the experiment is conducted.)


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Thermalfluids Lab-MEC 554/ LS 4/ Rev. 01-2016

Experiment ID:

Surface geometry:

Ambient airtemperature, T∞ :

Power input, :

Air velocity [m/s] Heater Temperature, Ts [

0C]

Ts - T∞ [0C] H [ W/(m·0C)]

Experiment ID:

Surface geometry:


Power input, :

Air velocity [m/s]Heater Temperature,

Ts [0C]

Ts - T∞ [0C] H [ W/(m·

0C)]

Experiment ID:

Surface geometry:


Power input, :

Air velocity [m/s]Heater Temperature,

Ts [0C]

Ts - T∞ [0C] H [ W/(m·

0C)]

thermofluid lab 2-part a

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