Chapter 12, Problem 12.64P

The spectral absorptivity ${\alpha }_{\lambda }$ and spectral reflectivity ${\rho }_{\lambda }$ for a spectrally selective, diffuse material are as shown.

(a) Sketch the spectral transmissivity ${\tau }_{\lambda }$

(b) If solar irradiation with ${\text{G}}_s=750W/m^2$ and the spectral distribution of a blackbody at 5800 K is incident on this material, determine the fractions of the irradiation that are transmitted, reflected, and absorbed by the material.

(c) If the temperature of this material is 350 K, deter- mine the emissivity $\epsilon$ .

(d) Determine the net heat flux by radiation to the material.