The inner and outer surfaces of a 30 cm thick wall in summer are 27C and...

 

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The inner and outer surfaces of a 30 cm thick wall in summer are 27C and 44C respectively. The outer surface of the wall exchanges heat by convection with ambient air which is at 40C with a convection heat transfer coefficient of 12 W/m.C. Solar radiation is incident on the surface at a flux rate of S W/m. The wall has a thermal conductivity of 1.5 W/m.C. The solar absorptivity of the outer surface is 0.8, assuming unit area of wall (1 m) and neglecting heat radiation (All answers must have the governing equations shown as well as the units for full credit!) a) Calculate the rate of heat flowing through the wall per unit area [5 pts] b) Find the rate of solar flux (S) incident on the wall [10 pts] 27C. 44C S W/m air, 40C h The inner and outer surfaces of a 30 cm thick wall in summer are 27C and 44C respectively. The outer surface of the wall exchanges heat by convection with ambient air which is at 40C with a convection heat transfer coefficient of 12 W/m.C. Solar radiation is incident on the surface at a flux rate of S W/m. The wall has a thermal conductivity of 1.5 W/m.C. The solar absorptivity of the outer surface is 0.8, assuming unit area of wall (1 m) and neglecting heat radiation (All answers must have the governing equations shown as well as the units for full credit!) a) Calculate the rate of heat flowing through the wall per unit area [5 pts] b) Find the rate of solar flux (S) incident on the wall [10 pts] 27C. 44C S W/m air, 40C h