A rectangular slab (k= 10 W/m-K) of thickness 15cm and inside temperature of 4000C is insulated by a materials of thickness 10cm (k= 30 W/m-k). The ambient air is at 280C and the outside convective heat transfer coefficient is 15 W/m2K. Determine the steady state heat transfer per unit surface area and the temperature of outside surface of the slab and the insulation.

Given,

δ1=15cm=0.15m $\hspace{1cm}$ (Thickness of slab)

K=10W/mK $\hspace{1.8cm}$ (Thermal conductivity of slab material)

t1=400℃=673K $\hspace{1.2cm}$ (Inside temperature of slab)

δ2=10cm=0.1m $\hspace{1.2cm}$ (Thickness of insulation)

Kins=30W/mK $\hspace{1.4cm}$ (Thermal conductivity of insulation material)

t4=28℃=301K $\hspace{1.4cm}$ (Ambient air temperature)

h=15W/m2K $\hspace{1.7cm}$ (Convective heat transfer coefficient of ambient air)

A=1m2 $\hspace{2.5cm}$ (cross sectional area …