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-   -   flow around an airfoil (http://www.cfd-online.com/Forums/fluent/29464-flow-around-airfoil.html)

Nicola March 7, 2002 11:54

flow around an airfoil
 
Please help me, i tried to simulate a flow around an airfoil (inviscid and laminar) using a C domain and a quad/map scheme(with gambit),but nothing works correctly.In inviscid flow,the velocity at the airfoil surface is not tangent and there is also a reverse flow and separation at high incidence.In laminar flow, the velocity profile at airfoil surface seems good but after some hundred iterations the solutions diverge.Which is the problem?The grid or using wrong solver?Please please please help me!

Thanks to everyone in advance! Bye.

cagri.metin.ege August 15, 2013 19:31

I suggest two things , which are first you should check mesh quality. The mesh quality consist of a lot of case, but you should notice first cell high that calculate from yplus. And then your mesh must increase ratio 1.2 or less. Other parameters are mesh ortogonalty that is mesh must be perpendecular to airfoil. On the other hand your mesh skew is less than 0.7 , you can check mesh skew in fluent or during preparing mesh, Important part is your solution must independent of mesh number. I had reversed flow problem, actually it is not problem, you should check boundary coundition, or cmesh lenght, it is far enough like 12 or 20 times chord lenght, or decrease skew quality. If you want to faster diverge , you have two way. First one; if you use density based increase count number or if you pressure based increase under relaxing factor. But your increasing parameter due to wrong diverge. good luck


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