(Solved): Problem 3: A diffuse and gray thin radiation shield of 0.35m diameter having inner and outer emis ...

Problem 3: A diffuse and gray thin radiation shield of $0.35\mathrm{m}$ diameter having inner and outer emissivity values of ${?}_{2i}=0.05$ and ${?}_{2o}=0.1$ is placed in between two concentric spherical surfaces. The spheres are diffuse-gray and have diameters of $0.2\mathrm{m}$ and $0.6\mathrm{m}$. The inner sphere has a surface temperature of $T_1=500\mathrm{K}$ and emissivity of ${?}_1=0.3$. The outer sphere has a surface temperature of $T_3=300\mathrm{K}$ and emissivity of ${?}_3=0.4$ a) Draw the resistance network and determine the surface temperature of the radiation shield. b) If the configuration of the radiation shield is inverted so that the new emissivity values are ${?}_{2i,\text{ new }}=0.1$ and ${?}_{2o,\text{ new }}=0.05$, what is the new surface temperature of the radiation shield?