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-   -   Unrealistic CL values... (http://www.cfd-online.com/Forums/cfx/95434-unrealistic-cl-values.html)

Echidna December 17, 2011 10:21

Unrealistic CL values...
 
Hello everybody.
I am currently making a CFD analysis of a racecar dual-element wing but i keep receiving unrealistic cl values. The value i get is of the order of 3.8 which is too good to be true for a dual-element wing!
The wing has a span of 1.5m and a chord of 320mm. I have set "air at 25deg" as the fluid, 1bar operating pressure, and 50m/s inlet air velocity.
I suspect that something is wrong with the mesh.. I have inflated the wing, setting the first layer thickness at 0.5mm and surface sizing at the wing surfaces at 5mm. I know that my mesh is a bit coarse but my computer power cannot withstand any more loads i am afraid..

Do you think that the meshing could give such a difference in CL and downforce values? Thanks all! :)

ghorrocks December 18, 2011 06:14

Yes, it certainly could. A bad mesh will make your results little better than random numbers.

There is a FAQ on simulation accuracy:
http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F


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