Question

(a) Schematically draw the spectral emissive power of two blackbodies with the temperature of 2400 K and 300 K (ie. EBA versus λ). What are the wavelengths at the maximum spectral emissive power? (5 pts) (b) A thin-walled plate separates the interior of a large furnace from surroundings at 300 K. The plate is fabricated from a ceramic material for which diffuse surface behavior may be assumed and the exterior surface is air-cooled. With the furnace operating at 2400 K convection at the interior surface may be neglected, and radiation from the surroundings (300 K) to the ceramic plate may be neglected too. If the temperature of the ceramic plate is not to exceed 1800 K under steady state, what is the minimum value of the outside convection coefficient, ho, which must be maintained by the air cooling system? Assume the irradiation reached the inner surface of the ceramic plate from the interior wall (2400 K) is due to emission from a blackbody at 2400 K. (15 pts) Ceramic 0.8 300 K0.3 7,-2400 K 111, I-1800 K 0 0 (um) Air ho,T 300 K

Answer 1

24-00 K 3o0 F Son Eebalance 1Soo -300