Reynolds Number Calculation

May 10, 2006, 05:46

Hi All,

Can any one tell me, whether there is any way to find the Reynolds Number from CFX directly? If we have to write expression what approach we have to use (assume the flow is not as simple as a flow through pipe)

Thanks in advance AP

May 10, 2006, 18:16

Hi,

CFX already reports a Reynolds number, but it is based on an average length and velocity scale so often has no physical relevance.

Yes, you can set up a CEL expression to calculate Reynolds number.

As for what approach you have to use, see a basic fluid dynamics textbook. You need to define a physically relevant length and velocity scale, and also define the fluid viscosity and density which requires some thought if they are not constant. For external flows this is usually the freestream velocity, density and viscosity.

Regards, Glenn Horrocks

May 10, 2006, 05:46	Reynolds Number Calculation	#1
AP Guest Posts: n/a	Hi All, Can any one tell me, whether there is any way to find the Reynolds Number from CFX directly? If we have to write expression what approach we have to use (assume the flow is not as simple as a flow through pipe) Thanks in advance AP

May 10, 2006, 18:16	Re: Reynolds Number Calculation	#2
Glenn Horrocks Guest Posts: n/a	Hi, CFX already reports a Reynolds number, but it is based on an average length and velocity scale so often has no physical relevance. Yes, you can set up a CEL expression to calculate Reynolds number. As for what approach you have to use, see a basic fluid dynamics textbook. You need to define a physically relevant length and velocity scale, and also define the fluid viscosity and density which requires some thought if they are not constant. For external flows this is usually the freestream velocity, density and viscosity. Regards, Glenn Horrocks

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