Rayleigh number
The Rayleigh number is a dimensionless number defined as the product of Grashof and Prandtl numbers. For free convection near a vertical wall, this number is
Rax,c=Grx,cPr = g β (Ts-T∞)x3
ν α
where
Ra Rayleigh number Gr Grashof number Pr Prandtl number g gravity Ts Temperature of surface T∞ Quiescent temperature ν kinematic viscosity α thermal diffusivityThe Rayleigh number is named after Lord Rayleigh.
