A flat plate is in a solar orbit 150,000,000 km from the sun. It is always oriented normal to the rays of the sun and both sides of the plate have a finish which has a spectral absorptance of 0.95 at wavelengths shorter than 3 μ m and a spectral absorptance of 0.06 at wavelengths longer than 3 mm. Assuming that the sun is a 5550 K blackbody source with a diameter of 1,400,000 km, determine the equilibrium temperature of the plate.GIVENA flat plate in solar orbit oriented normal to the rays of the sunDistance from the sun (R) = 150,000,000 km = 1.5 x 1011 mSpectral absorplatace (ελ) of both sides ελ1 = 0.95 for λ1 ελ2 = 0.06 for λ1 > 3 μ mASSUMPTIONSThe sun is a black body at Ts = 5550 KSun diameter (Ds) = 1,400,000 km = 1.4 x 109m

Transcribed Image Text:

0.95 Sun Plate +D, 0.06- 3 um