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 heat …show more content…

| Watt meter Q | (y2-y1) K | (x2-x1) m | dTdx | Thermal conductivity kH W/mK | 1 | 2.5 | -2 | 0.02 | -100 | 50.93 | 2 | 5 | -4 | 0.02 | -200 | 50.93 | 3 | 7 | -4.6 | 0.02 | -230 | 62 | Average Thermal Conductivity, kH | 54.62 |

Table 2(ii): Calculation for thermal conductivity, kS Test No. | Watt meter Q | (y2-y1) K | (x2-x1) m | dTdx | Thermal conductivity kS W/mK | 1 | 2.5 | -4.5 | 0.04 | -112.5 | 45.27 | 2 | 5 | -16.1 | 0.04 | -402.5 | 25.31 | 3 | 7 | -19.1 | 0.04 | -477.5 | 29.86 | Average Thermal Conductivity, kS | 33.48 |

Table 2(iii): Calculation for thermal conductivity, kC Test No. | Watt meter Q | (y2-y1) K | (x2-x1) m | dTdx | Thermal conductivity kC W/mK | 1 | 2.5 | -0.5 | 0.02 | -25 | 203.71 | 2 | 5 | -0.6 | 0.02 | -30 | 339.51 | 3 | 7 | -0.5 | 0.02 | -25 | 570.38 | Average Thermal Conductivity, kC | 371.2 |

Calculation using thermal