Chapter 2, Problem 2.61P

A thin aluminum sheet with an emissivity of 0.14 on both sides is placed between two very large parallel plates maintained at uniform temperatures of T1=720 K and T2=560 K. The emissivities of the plates are ɛ1=0.76 and ɛ2=0.85. Determine the net rate of radiation heat transfer between the two plates per unit surface area of the plates, and the temperature of the radiation shield in steady operation.

A radiation shield that has the same emissivity 3 on both sides is placed between two large parallel plates, which are maintained at uniform temperatures of T1 = 650 K and T2 = 400 K and have emissivities of E1 = 0.6 and E2 = 0.9, respectively. Determine the emissivity of the radiation shield if the radiation heat transfer between the plates is to be reduced to 15 percent of that without the radiation shield

2. A thin aluminum sheet with an emissivity of 0.15 on both sides is placed between two very large parallel plates, which are maintained at uniform temperatures T1 = 900 K and T2 = 650 K and have emissivities ?1 = 0.5 and ?2 = 0.8, respectively. Determine the net rate of radiation heat transfer between two plates per unit surface area of the plates and compare the result with that without the shield