Grashof number, duct in air

Symbol
$\mathrm{Gr}_{da}$
Formulae
$\frac{g \beta_{gas} {L_d}^3}{{\nu_{gas}}^2} \left(\theta_{de}-\theta_{film}\right)$
Used in
$\mathrm{Nu}_{da}$
$\mathrm{Ra}_{gas}$