Question

Consider steady heat transfer between two large parallel plates at constant temperatures of T1 = 210 K and T2 = 150 K that are L = 2 cm apart. Assume that the surfaces are black (emissivity ε = 1). Determine the rate of heat transfer between the plates per unit surface area assuming the gap between the plates is filled with atmospheric air.

Answer 1

`Q=81.56\ W/m^2`

Step-by-step explanation:

Given that

`T_1= 210 K`

`T_2= 150 K`

Emissivity of surfaces(∈) = 1

We know that heat transfer between two surfaces due to radiation ,when both surfaces are black bodies

`Q=\sigma (T_1^4-T_2^4)\ W/m^2`

So now by putting the values

`Q=\sigma (T_1^4-T_2^4)\ W/m^2`

`Q=5.67* 10^(-8)(210^4-150^4)\ W/m^2`

`Q=81.56\ W/m^2`

So rate of heat transfer per unit area

`Q=81.56\ W/m^2`