A composite wall has 100 mm brick of conductivity 0.30 W/(m °C), followed by 150 mm polyurethane insulation of conductivity 0.05 W/(m °C). Exposed brick and insulation surfaces are 45°C and 10°C. Find interface temperature in °C (one decimal).
Per-area thermal resistances are Rb=0.1/0.30=1/3 and Ri=0.15/0.05=3. Heat flux is (45−10)/(1/3+3)=10.5 W/m². Brick temperature drop is 10.5/3=3.5°C, so interface temperature=45−3.5=41.5°C.
More Heat and Mass Transfer questions
GATE 2020 AG Q44– Steam at121°C sterilizes pineapple juice by direct injection. Juice enters80°C and diluted…
GATE 2020 AG Q45– Oil enters a counterflow concentric heat exchanger at120°C,20 kg/min; water enters the…