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kostas January 3, 2009 09:41

Problem with turbulent models
 
Hi. I have a airfoil and when i solute it with a k-e model (enhanced wall) with y+=0.2-1.3, i take wrong results... When i solute it with spalart-almaras with same y+, i take a good approximation. Why occur this with k-e model? What do must i, for use the k-e model? expect the configuration of y+, must i config other parameters??

zongtwi January 3, 2009 11:54

Re: Problem with turbulent models
 
If your Y+ values is around 1, you should use the enhance wall treatment with the k-e model. This should improve your results.

Hope that helps.

igor January 3, 2009 14:19

Re: Problem with turbulent models
 
why do you not use k-e model and a mesh with y+ = 20-40?

kostas January 3, 2009 16:45

Re: Problem with turbulent models
 
So. I solute the airfoil with k-e model and i see after that i have Y plus approximately 0.4-0.5. The results are wrong (the low pressure of up section is at back of section which is wrong because my experiments have the low pressure in front of section.).

when i try to use wall functions, must make a big length of first node and again i take the same results...

Only, with spalart-allarmas take approximately good results..

Why does not work the k-e model?? Must i look and other parameters for work the k-e model???

Please, help me someone....

uabdillah January 4, 2009 22:47

Re: Problem with turbulent models
 
I have trouble with my study about flow arround type D cylinder with cutting angle 65 degree with Re=53000. this study using fluent 6.2, i think my meshing is good but still cannot reach intensity 0.2 and length scale 0.01. I hope you can to solve my problem


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