The kinematic viscosity (also called momentum diffusivity) is the ratio of the dynamic viscosity $μ$ to the density $ρ$.

It is a convenient concept when analyzing the Reynolds number, which expresses the ratio of the inertial forces to the viscous forces.

Symbol
$\nu_{\mathrm{gas}}$
Unit
m2/s
Formulae
 $- 1.1555 \cdot 10^{-14} T_{air}^{3} + 9.5728 \cdot 10^{-11} T_{air}^{2} + 7.604 \cdot 10^{-9} T_{air} + 3.4484 \cdot 10^{-6}$ air at 1 atm (Dumas&Trancossi2009) $\frac{\eta_{\mathrm{gas}}}{\rho_{\mathrm{gas}}}$ general formula for gases
Related
$\eta_{\mathrm{gas}}$
$\rho_{\mathrm{gas}}$
Gas density [kg/m³]
Used in
$\eta_{\mathrm{gas}}$
$F_{\mathrm{pt}}$
$\mathrm{Gr}_{\mathrm{c}}$
$\mathrm{Gr}_{\mathrm{encl}}$
$\mathrm{Gr}_{\mathrm{L}}$