Chapter 15 Steady Heat Conduction3-52A wall consists of horizontal bricks separated by plaster layers. There are also plaster layers on each side of the wall, and a rigid foam on the inner side of the wall. The rate of heat transfer through the wall is to be determined. Assumptions1Heat 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 Heat transfer by radiation is disregarded. PropertiesThe thermal conductivities are given to be k= 0.72 W/m⋅°C for bricks, k= 0.22 W/m⋅°C for plaster layers, and k= 0.026 W/m⋅°C for the rigid foam. Analysis We consider 1 m deep and 0.33 m high portion of wall which is representative of the entire wall. The thermal resistance network and individual resistances are R2R3R4R5R6R7T∞2RRiT∞1RRhALkARRRLkALiconvfoamplastersideplastercentero===°×=°======,((.)..(.)..)..
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