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-   -   Vortex Generators (http://www.cfd-online.com/Forums/fluent/40788-vortex-generators.html)

Ben Cho April 30, 2006 12:51

Vortex Generators
 
Hi all,

I've been trying to model the effect of vortex generators in delaying stall on a NACA0012 wing using fluent. I know that they delay stall since I've experimentally confirmed this, but when I run my cases in FLUENT, I get no effect. This is my case:

Wall bounded flow. k-epsilon tuburbulence model, realizable, enhanced wall treatment, pressure gradient effects. Re = 100 000. turb intensity = 1.5%. turb length = 0.0077m.

Basically, I'm modeling a point where on the old wing, we would be in the post stall region, but in the wing with the voretex generators, I would still be pre-stall.

Note for enhanced wall treatment, my y+ is less than 0.35 for the wing and less than 1.4 for the boundaries.

Any ideas? I'm getting really frustrated :).

Thanks in Advance. Ben

Riaan May 5, 2006 00:59

Re: Vortex Generators
 
Well, for starters, predicting CLmax is not an easy task. Doing CFD of the vortex generators (sub boundary layer I assume) is going to be tough, because you need a lot of cell density to capture the vortex core.

I would probably saying that if you do a particle trace from the vortex generators and see no vortex - then your grid is too course.



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