- #1

- 624

- 11

## Homework Statement

Two parallel plates plates are maintained at temperatures ##T_L## and ##T_R## respectively and have emissivities ##\epsilon_L## and ##\epsilon_R## respectively. Given the Stephan-Boltzmann constant ##\sigma##, express the net energy transfer rate per area from the left plate (L) to the right plate (R).

## Homework Equations

## The Attempt at a Solution

The way they solve it is by calculating the transfer rate to the right and left like this: $$I_R=\epsilon_L\sigma T_L^4+(1-\epsilon_L)I_L$$ and $$I_L=\epsilon_R\sigma T_R^4+(1-\epsilon_R)I_R$$ and the net transfer is $$I_{net}=I_R-I_L$$ I am confused about the ##(1-\epsilon)I## term. Where does that come from? How can ##I_L## which is the energy leaving the right plate, contribute to the flux of energy TO the right plate? It is already there, within the right plate.