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Philip July 12, 2000 14:20

Richardson No.
Could anyone give me a definition of Richardson no. , I think its someting to do with density gradients I think, and how does it arise in swirling flows if the flowfield is incompressible. Thanks for the help.


Jin Wook LEE July 12, 2000 21:40

Re: Richardson No.
Dear Philip

There are severalm, but entirely different, Richardson number in fluid mechanics.

For mixed convection, Richardson number is defined as

Ri = Gr / Re**2

Where, Gr = Grashof #, Re = Reynolds #

For swirling flow, gradient Richardson numberis the ratio of body force(centrifugal force) to the inertial force, and defined as,

Ri = [(k/epsilon)**2]*[U/R**2]*[partial(UR)/partial(R).

Where, U = vel. in the streamwise direction and R = local radius of curvature.

And you may find similar definition for Richardson number for swirling flow.

Sincerely, Jinwook

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