# Convection heat transfer coefficient, object to gas

Symbol
$h_{conv_{og}}$
Unit
W/(K.m$^2$)
Formulae
 $\frac{\mathrm{Nu}_{og} k_{gas}}{\delta _{d}}$ Riser closed at both ends (Anders) $\frac{\mathrm{Nu}_{og} k_{gas} \left(\frac{0.46 D_{di}}{D_{o}} + 0.54\right)}{\delta _{d}}$ Riser open at both ends (Anders) $\frac{\mathrm{Nu}_{og} k_{gas}}{L_{d}}$ Riser open at top and closed at bottom (Anders) $\frac{\mathrm{Nu}_{og} k_{gas}}{L_{d}}$ General case (Hartlein & Black) $\frac{\mathrm{Nu}_{og} k_{gas}}{\delta _{d}}$ Riser open at both ends, 133 ≤ $Ra$ ≤ 7000 (Hartlein & Black IIa)
Related
$D_{di}$
$D_{o}$
$\delta _{d}$
$k_{gas}$
$L_{d}$
Used in
$h_{conv_{gd}}$
$W_{conv_{og}}$