Cableizer

Convective heat transfer riser/tray—air

Convection heat transfer from duct outer surface to ambient air.

Symbol
$W_{conv,ext}$
Unit
W/m
Formulas
$\pi D_{do} h_{conv,ext} \left(\theta_{de}-\theta_{air}\right)$riser
$\left(w_{t}+2t_{t}\right) h_{conv,CA} \left(\theta_{to,c}-\theta_{air}\right)+\left(w_{t}+2t_{t}\right) h_{conv,BA} \left(\theta_{to,b}-\theta_{air}\right)+2\left(h_{t}+2t_{t}\right) h_{conv,SA} \left(\theta_{to,s}-\theta_{air}\right)$tray
Related
$D_{do}$
Outer diameter duct [m]
$h_{conv,ext}$
Heat transfer coefficient convection riser/tray—air [W/(K.m$^2$)]
$h_{conv,tray}$
Heat transfer coefficient convection riser/tray—air [W/(K.m$^2$)]
$h_{t}$
Height (inner) [m]
$\pi$
Archimedes' constant $\pi$
$t_{t}$
Thickness wall [m]
$\theta_{air}$
Ambient air temperature [°C]
$\theta_{de}$
Temperature duct outer surface [°C]
$w_{t}$
Width (inner) [m]
Used in
$T_{4iii}$
Thermal resistance ambient [K.m/W]