Information:-
As air is a mixture of gases the value of prandtl number for gases varies form .7 to 1 and Pr number is the ratio of molecular diffusion of momentum to molecular diffusion of heat
Mathematically
Pr= Kinematic viscosity / Thermal Difussivity By putting Kinematic viscosity = Dynamic Viscosity / Density and Thermal diffusivity = Thermal conductivity of fluid / density of fluid x specific heat coefficient of fluid this will give us Pr = dynamic viscosity x specific heat coefficient / thermal conductivity.
