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-   -   Y+ Range for RNGk-epsilon Turbulence Method (http://www.cfd-online.com/Forums/main/16168-y-range-rngk-epsilon-turbulence-method.html)

Velan December 31, 2008 05:05

Y+ Range for RNGk-epsilon Turbulence Method
 
Hi all

I simulated fully supersonic flow of scramjet inlet along with cowl using openFOAM. I used RNGk-epsilon Turbulence Method to compute turbulence. My freestream mach number is in the range of 2-3. When i checked the y+ range, it came in the range of 10-600. Near the separation region y+ is very high. I dont know what range of y+ should be for RNGk-epsilon method. Can you please tell me how to calculate y+ ? Does anybody having idea about it ?

- Velan

John S. January 6, 2009 11:50

Re: Y+ Range for RNGk-epsilon Turbulence Method
 
K-epsilon models typically need a y+ of around 30 to be accurate as you're not trying to resolve the boundary layer. There's a lot of information about y+ located in the wiki. I find it a little odd, though, that you're reporting high y+ near a separated region inthat y+ is directly related to wall shear. Areas of low wallshear, such as within a separated region, typically have low y+ values.


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