1. CONDUCTIVITY OF LIQUIDS AND GASSES EXPERIMENT TD 1002D

2. Objectives
To find any power losses and calibrate the equipment using air and liquid .
To find the thermal conductivity of test liquids and gasses and compare with typical values.

3. Introduction
This experiment has three concentric cylinders. The inner cylinder contains an electric heater (the heat source).
The test liquid or gas forms a second, thin cylinder around the heat source.
The third cylinder cooled by water surrounds them both to make a heat sink.
One end cap is removable to allow the unit to be easily cleaned when changing from one fluid to another.

4. Heat passes by conduction from the heat source, through the test liquid or gas, to the heat sink.
Thermocouples measure the temperature on the inside and outside edges of the cylinder of test liquid or gas.
which also supplies the cold water feed and drain for the heat sink Caps of thermally-insulating material at the ends of the cylinders reduce heat loss

5. Suitable test fluids include:
Normal, dry air
Carbon dioxide
Castor oil

6. Equipment's
Base unit:TD1002 Heat Transfer Experiments Base Unit

7. TD1002D

8. Procedure brass material Procedure 1: calibration using air
1- Make sure the experiment is clean and dry.
2 - Connect and set up your experiment (TD1002D).
3 - Create a blank results table

9. 4 - Use an accurate thermometer to check the local ambient air temperature for reference. 5 - Open the water outlet valve to start the water flowing, then switch on heater and set to 90 watts power.
CALIBRATION WITH AIR
Ambient Temperature=
Heater Power (W)
T1 (˚C)
T2 (˚C)
Average Temperature
T1-T2
Calculated K for air
Calculated Power
Power Loss
 90
80 
70 
60 

10. 6 - Wait for temperature to stabilize and then record T1 and T2
6 - Wait for temperature to stabilize and then record T1 and T Repeat the test at heater powers in decreasing steps of 10 w. 8 - Switch off the heater and water supply. 9 - Find the average temperature across the radial gap in Celsius 𝑇 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 = 𝑇 1 + 𝑇 Use the average temperature to the given value of thermal conductivity from the equation 𝐾=7× 10 −5 𝑇 𝑎𝑣𝑒

11. 11 - Now calculate the power using this equation 𝑊= 𝐾 𝐴𝑠 ∆𝑇 𝑟 𝑐𝑎𝑝 12 - Subtract this calculated power from the heater power to find the power loss in the equipment Plot a chart of thermal conductivity (vertical-axis) against temperature average in Celsius (horizontal-axis) and calculation the slope.

12. Data about the experience
𝐷 𝑎𝑣𝑒 =( 𝐷 𝑖𝑛 + 𝐷 𝑜𝑢𝑡 )/2
𝐷 𝑎𝑣𝑒 =( )/2=40.51mm
𝑟 𝑎𝑣𝑒 = 𝐷 𝑎𝑣𝑒 /2=20.255mm
L=100 mm
As=2*pi* 𝑟 𝑎𝑣𝑒 *L= 𝑚 2
𝑟 𝑐𝑎𝑝 =0.51mm

13. Results The relationship between the thermal conductivity against temperature average in Celsius and calculation the slope

14. Procedure 2: Testing liquids
1- Make sure the experiment is clean and dry. 2 - Connect and set up your experiment (TD1002D). 3 - Add your chosen test fluid (Castor oil). 4 - Create a blank results table

15. Power loss from calibration chart (W)
Test Fluid: Castor oil
Ambient Temperature:
Radial Gap:0.51mm
Typical textbook value of K at room Temperature:
Heater Power (W)
T1 (˚C)
T2 (˚C)
Average Temperature
T1-T2
Power loss from calibration chart (W)
Corrected power (W)
Calculated K

16. 5 - Use an accurate thermometer to check the local ambient air temperature for reference. 6-Open the water outlet valve to start the water flowing, then switch on heater and carefully adjust the heater power until the temperature difference is around 10 degrees. 7 - Wait for temperature to stabilize and then record T1 and T Repeat the test at heater powers in decreasing steps of 10 w. 9 - Switch off the heater and water supply.

17. 10 - Find the average temperature across the radial gap in Celsius 𝑇 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 = 𝑇 1 + 𝑇 Use the average temperature to the given value of thermal conductivity from the equation 𝐾=7× 10 −5 𝑇 𝑎𝑣𝑒 Now calculate the power using this equation 𝑊= 𝐾 𝐴𝑠 ∆𝑇 𝑟 𝑐𝑎𝑝

18. 13 - Subtract this calculated power from the heater power to find the power loss in the equipment.
14 - Plot a chart of thermal conductivity (vertical-axis) against temperature average in Celsius (horizontal-axis) and calculation the slope.

19. Results The relationship between the thermal conductivity against temperature average in Celsius and calculation the slope