Answer to Question #256760 in Mechanical Engineering for Jnl

Question

Determine the net radiant-heat exchange between two parallel oxidized iron plates when the distance between them is 2 ft. and each plate measures 10 by 10 ft. The surface of one is at 200 °F and the other is at `100°F.

Answer 1

$T_1=200°F$

$T_2=100°F$

$Q_{net}=\frac{\sigma(T_1^4-T_2^4)}{\frac{1}{\epsilon_1}+\frac{1}{\epsilon_2}-1}$

$\epsilon_1=0.9$

$\epsilon_2=0.4$

$\sigma=5.67*10^{-8}$

$Q_{net}=\frac{5.67*10^{-8}(200^4-100^4)}{\frac{1}{0.9}+\frac{1}{0.4}-1}$

$=32.5723W/ft^2$