Emissivity e varies with zenith angle according to e = E*cos(theta)

  • Thread starter Callisto
  • Start date
  • #1
41
0

Main Question or Discussion Point

If the emissivity e varies with zenith angle according to e = E*cos(theta) where E is the emissivity normal to the surface. Would this surface be an isotropic source of radiation?

Well, since e varies with angle then the flux density must vary accordingly so the surface would radiate anistropically.

Anybody disagree?
Callisto
 

Answers and Replies

  • #2
selfAdjoint
Staff Emeritus
Gold Member
Dearly Missed
6,764
5
This cosine law is like the one for intensity of incoming solar radiation, and that's a cylinder, so I agree, anisotropic.
 
  • #3
Bystander
Science Advisor
Homework Helper
Gold Member
5,131
1,146
"Anisotropic" for a point on a surface; integrate intensity at any point above an infinite plane surface, and it's isotropic.
 

Related Threads for: Emissivity e varies with zenith angle according to e = E*cos(theta)

  • Last Post
Replies
1
Views
886
  • Last Post
Replies
7
Views
1K
Replies
5
Views
4K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
3
Views
5K
Replies
5
Views
4K
Replies
3
Views
870
Replies
5
Views
4K
Top