Solar radiation heat transfer to surface

Solar radiation heat transfer to surface of GIL by sun. It is assumed that the sun shines directly from above onto an area of the length (1 m) multiplied with the diameter $D_o$ of the cylindrical object (and not half its circumference $\pi D_o/2$).

Symbol
$W_{sun}$
Unit
W/m
Formulae
$D_{o} H_{sun} \sigma_{sun}$
Related
$D_{o}$
$H_{sun}$
Used in
$T_{4iii}$
$T_{rad_{sun}}$
$W_{tube}$