10 - Thermal Radiators Flashcards
1
Q
Emitted Power (Pm)
A
A function of:
* Cross Sectional Area (m2)
* Exitance (W/m2)
2
Q
Exitance (M)
A
The power per unit area leaving an object (W/m2)
3
Q
Emissivity (e)
A
Objects material property that accounts for the difference in radiation between the ideal (blackbody) and actual (graybody)
Black bodies: a = e = 1
Gray bodies: e + p = 1
4
Q
What is attenuation?
A
How light moves through a given space
5
Q
Spreading
A
- Energy spreads spherically; power density decreases
- One way trip
6
Q
Scattering
A
Redirection of radiated energy by particulates
- Re-direction of light
7
Q
Absorption
A
Different elemental molecules react to wavelengths differently
8
Q
Turbulence
A
Index of refraction variations cause light to bend in various directions
- Temperature affects changes
