[복사열전달] Selective absorber

Consider a selective absorber that has a diffuse but wavelength-dependent emittance, which can be approximated by: ϵλ = 0.9 when λ < 2 µm and ϵλ = 0.25 when λ > 2 µm (a) The absorber is irradiated by the sun with a strength of qsolar = 1000 Wm−2 from a direction which is 60 from the surface normal. What is the power flux [Wm−2] absorbed by the selective absorber from the solar irradiation?

(b) The environment at 20C also emits thermal radiation to the absorber. Assume the radiation from the envi...