Richardson Number -- from Eric Weisstein's World of Physics

Fluid Mechanics "> Convection v

Units and Dimensional Analysis "> Dimensionless Parameters v

Richardson Number

A dimensionless parameter whose values determines is convection is free or forced, defined by

where g is the gravitational acceleration, is the thermal expansion coefficient, is the temperature difference, u and U are the velocity scale, L is the length scale, and is the internal Froude number.

For flow near a heated wall,

where g is the gravitational acceleration, is the standard density, is the thermal expansion coefficient, K is the Kármán constant, H is the rate of heat transfer per unit area, is the density, and is the heat capacity, and T is the temperature.

The height at which the Richardson number equals 1 is known as the Monin-Obukhov length.

Convection, Forced Convection, Free Convection, Monin-Obukhov Length