Two large parallel plates are maintained at (T_{1}=500) and (T_{2}=300 mathrm{~K}), respectively. The hot plate has an

Question:

Two large parallel plates are maintained at \(T_{1}=500\) and \(T_{2}=300 \mathrm{~K}\), respectively. The hot plate has an emissivity of 0.9 while that of the cold plate is 0.7 .

(a) Determine the radiation heat flux without and with a radiation shield formed of a flat sheet of foil placed midway between the two plates. Both sides of the shield have an emissivity of 0.05.

(b) A scheme is proposed to further reduce the radiation heat flux between the plates by adding more shield material, achieved by corrugating the flat shield material. Calculate the radiation heat flux associated with the corrugated shield of the sketch with a crease angle of \(\alpha=\pi / 4\). Is the scheme successful in reducing the heat flux?

(c) Graph the radiation heat flux between the plates with no shield, with a flat shield in place, and with a corrugated shield in place over the range \(0 \leq \alpha \leq \pi\). Explain the behavior evident in your graph.
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