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-   -   Turbulence Specification Method (http://www.cfd-online.com/Forums/fluent/36040-turbulence-specification-method.html)

Srivatsan V. Rajagopalan March 16, 2005 14:48

Turbulence Specification Method
 
I am using a K-Epsilon turbulence modelling for simulatig a supersonic compreeible turbulent flow in a nozzle. Can anyone pls tell me what to specify in "Turbulence Specification Method" in the "inlet panel" of Boundary conditions?

The Help in Fluent uses a "Intensity and Hydraulic Diameter" Can any one explaain me why it is so?

Srivatsan

ROOZBEH March 17, 2005 04:11

Re: Turbulence Specification Method
 
Hi; You must set values as boundary condition for turbulence model equations, for example "k and e equations". You should set a value for k and a value for epsilon. But it is very difficult for a user to know what value is better to set. Instead, you can set values for turbulence intensity and viscosity ratio or hydrolic diameter. Fluent uses these values for boundary conditions. ROOZBEH

Srivatsan V. Rajagopalan March 17, 2005 11:49

Re: Turbulence Specification Method
 
HI Roozbez! Thanks for your suggstion. As mentioned by U, I use only Hydraulic diameter. Can U pls take a little time in eplaining me how to define Viscosity ratio? It depends on what? Thnk you in advance!

mahmoud April 4, 2005 00:50

Re: Turbulence Specification Method
 

mahadevan.swamy May 20, 2009 20:24

Hydraulic Diameter
 
Hi,

I am making a 2D case analysis by have a 2D body in a tunnel (plane). I don't know how to find the hydraulic diameter or the length scale of this problem. I do know that the air will be travelling at 27.76 m/s around the body. How do I calculate the hydraulic diameter for this 2D case? Any ideas? Thanks in advance

Swamy

shaoda169 January 31, 2011 06:39

Quote:

Originally Posted by mahadevan.swamy (Post 216787)
Hi,

I am making a 2D case analysis by have a 2D body in a tunnel (plane). I don't know how to find the hydraulic diameter or the length scale of this problem. I do know that the air will be travelling at 27.76 m/s around the body. How do I calculate the hydraulic diameter for this 2D case? Any ideas? Thanks in advance

Swamy

please refer to this website. http://support.esi-cfd.com/esi-users/turb_parameters/


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