OpenVSP (CL x alpha) incorrect

[Pedro André]

Hello, im new to openVSP and to the group so if i am posting in wrong place excuse me. 

So, my question is, i modeled a wing on openVSP and running on openVSP AERO i have got a CL x alpha curve that is a little strange, it just  shows stall near 80 degrees of AoA, i thought it should stall earlier, something about 20 degrees, could someone show me what im doing wrong? The labels are in portuguese, but in vertical axis is Cl and CDtotal and in horizontal axis is AoA. And i have another question, i used Mach=0,075, 25m/s, when i put bigger Mach M=0150 the CL increase annormaly, instead of being equal or similar to previous plot, some tip about it? Thanks ever since.

[Pedro André]

I am using 3.12.1 openVSP version, in a previous manual in website i read that i shoul do some kind of adjustment in the root of the wing because openVSP does not recognize the gap between the junction, i dont know if matters, just to give more info, thanks.

[Rob McDonald]

What you are seeing near 80 degrees is not stall, it is a different effect that doesn't make sense because the wing would have separated long before that.

VSPAERO can not predict stall.

Rob

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[Felix Finger]

See this post:
https://groups.google.com/forum/#!topic/openvsp/gDmkN4qdZ8U

VSPAERO -- in either thin-surface VLM or thick-surface Panel methods is a potential theory code that has no ability to predict viscous effects including separation.Don't use it to find CLmax or alpha_stall

[corp...@gmail.com]

If you want to use in some useful way the results of VSPAero and for the reasons explained above, I would suggest you to limit the alpha range to 8-10 degrees for clean configuration.

Corrado