preview

Heat Conduction Along a Composite Bar

Decent Essays
Open Document

Heat Conduction along a Composite Bar
Objective
To study the conduction of heat along a composite bar and evaluate the overall heat transfer coefficient.
Theory
Thermal conduction is the mode of heat transfer which occurs in a material by virtue of a temperature gradient within it. A solid is chosen for the demonstration of pure conduction since both liquids and gasses exhibit excessive convective heat transfer. In a practical situation, heat conduction occurs in three detentions, a complexity which often requires extensive computation to analyse. In the laboratory, a single dimensional approach is required to demonstrate the basic law that relates rate of heat flow to temperature gradient and area.
For steady flow along the bar, the …show more content…

The linear test piece is supplied with interchange samples of conductors and insulators to demonstrate the effects of area, conductivity and the important features of unsteady state conditions may be demonstrated.
The apparatus may also be used to measure thermal conductivity of various solid materials by clamping a sample of specific dimensions between the hot and cold element.

Experimental Procedure
First, an intermediate position was selected for the heater power control and sufficient time for a steady state condition to be achieved was allowed before recording the temperature at all six sensor points and the input power reading on the wattmeter. After each change, sufficient time to achieve steady state conditions was allowed. 10 minutes was waited before the reading for 2.5W is read, 5 minutes was waited before the reading for both 5W and 7W are read. All results was recorded and tabulated under the table below. Test No. | Wattmeter Q (watts) | T1 (°C) | T2 (°C) | T3 (°C) | T7 (°C) | T8 (°C) | T9 (°C) | 1 | 2.5 | 35.6 | 34.4 | 33.6 | 29.1 | 29 | 28.6 | 2 | 5 | 49.4 | 47 | 45.4 | 29.3 | 29.1 | 28.7 | 2 | 7 | 53 | 50 | 48.4 | 29.3 | 29.1 | 28.8 |

Results
The temperature profile in the heater and cooler is plotted to extrapolate the respective outer surface temperatures (THS and TCS)

Heater’s Temperature versus Distance
Temperature
Distance

Cooler’s Temperature versus

Get Access
Related
Get Access