Thermodynamics HW Solutions 191

# Thermodynamics HW Solutions 191 - Chapter 15 Steady Heat...

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Chapter 15 Steady Heat Conduction 3-57 A composite wall consists of several horizontal and vertical layers. The left and right surfaces of the wall are maintained at uniform temperatures. The rate of heat transfer through the wall, the interface temperatures, and the temperature drop across the section F are to be determined. Assumptions 1 Heat transfer is steady since there is no indication of change with time. 2 Heat transfer through the wall is one-dimensional. 3 Thermal conductivities are constant. 4 Thermal contact resistances at the interfaces are disregarded. Properties The thermal conductivities are given to be k A = k F = 2, k B = 8, k B C = 20, k D = 15, k E = 35 W/m °C. Analysis ( a ) The representative surface area is A = × = 012 1 012 .. m 2 . The thermal resistance network and the individual thermal resistances are T 1 R 1 R 3 R 2 R 4 R 5 R 6 R 7 T 2 C/W 16 . 0 ) m 04 . 0 ( C) W/m. 8 ( m 05 . 0 C/W 06 . 0 ) m 04 . 0 ( C) W/m. 20 ( m 05 . 0 C/W 04 . 0 ) m 12 . 0 ( C) W/m. 2 ( m 01 . 0
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## This note was uploaded on 01/14/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.

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