Radiation heat transfer, duct to air

Radiation heat transfer from duct outer surface to ambient air.

Symbol
$W_{rad,da}$
Unit
W/m
Formulae
$\sigma \pi D_{do} \epsilon_{do} \left(\left(\theta_{de}+\theta_{abs}\right)^4-\left(\theta_{air}+\theta_{abs}\right)^4\right)$
Related
Used in