Cableizer ®

Length duct

The length of a duct for riser/J-tube exposed to air (and solar radiation).

Symbol
$L_{d}$
Unit
m
Used in
$\mathrm{Gr}_{ext}$
Grashof number riser—air
$\mathrm{Gr}_{gd}$
Grashof number gas—duct
$\mathrm{Gr}_{og}$
Grashof number cable—gas
$h_{conv,ext}$
Heat transfer coefficient convection riser—air [W/(K.m$^2$)]
$h_{conv,gd}$
Heat transfer coefficient convection gas—duct [W/(K.m$^2$)]
$h_{conv,int}$
Heat transfer coefficient convection cable—riser [W/(K.m$^2$)]
$h_{conv,og}$
Heat transfer coefficient convection cable—gas [W/(K.m$^2$)]
$\mathrm{Nu}_{int}$
Nusselt number cable—riser
$\mathrm{Nu}_{og}$
Nusselt number cable—gas
$\mathrm{Ra}_{ext}$
Rayleigh number riser—air