convergence problem

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Farivar

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Apr 12, 2024, 8:14:10 PMApr 12
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Hello,

I'm currently working on a project analyzing the NACA 2412 winglet, but I'm having trouble getting my results to converge. I would greatly appreciate some assistance in modifying the options shown in the attached pictures.

Thanks.

Screenshot 2024-04-12 at 8.13.16 PM.png
Screenshot 2024-04-12 at 8.13.44 PM.png

Rob McDonald

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Apr 12, 2024, 11:44:16 PMApr 12
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The CFDMesh you've generated is not being used by the VLM analysis -- they are separate things.

The VLM uses a mesh derived from the on-screen wireframe.  You should look at that for the number of spanwise and chordwise panels.  Also, look at the VSPAERO viewer to judge your solution.

The convergence actually looks about like expected, it will bounce around a bunch like that.

Why on earth are you running 21 AoA on a VLM analysis?  Look at your CL vs. Alpha, CM vs. CL and CL vs. CD -- do you really need 21 points to define those curves?

Rob

Farivar

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Apr 13, 2024, 12:02:04 AMApr 13
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I am trying to see is the difference between zero ,30 , 75 degree dihedral winglet designs .so after AoA12 when  stall happens I really don't need to go further. Unfortunately,I didn't find any source to learn the effects of changing Advance Flow Conditions , Stall Models ,Run mode , Panel method , Stall Method Could you please guide me with these? 
winglet 30-1.vsp3
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