Consider a material that is gray, but directionally selective with (, ) 0 5(1 cos ) Determine the hemispherical absorptivity when collimated solar flux irradiates the surface of the material in the direction 45 and 0 Determine the hemispherical emissivity B of the material ...

KNOWN A gray but directionally selective material with a 0 4 051coso FIND ...

Consider a material that is gray, but directionally selective with (, ) = 0.5(1 cos

Question:

Consider a material that is gray, but directionally selective with αθ (θ, Φ) = 0.5(1 – cos Φ). Determine the hemispherical absorptivity α when collimated solar flux irradiates the surface of the material in the direction θ = 45° and Φ = 0°. Determine the hemispherical emissivity B of the material.