Convection heat transfer, object to duct

Radiation heat transfer from envelope around cables to inner wall of the duct used for riser/J-tube.

Symbol
$W_{conv,od}$
Unit
W/m
Formulae
$h_{conv,od} \pi F_{eq} D_o \left(\theta_e-\theta_{di}\right)$Chippendale
$W_{conv,og}+W_{conv,gd}$Anders / Hartlein & Black