Learning Forum

[rikyfritz95]

Hello,

I'm trying to optimize the shape of an airfoil following the tutorial on the "maximization of the lif over drag ratio", but when I try to evaluate the observable (force) it shows me this error:

999999: mpt_accept: error: accept failed: Invalid argument

What does it mean? It doesn't happen if I try to evaluate other observables like pressure drop.

Thanks for your help

[DrAmine]

Hard to say why. Can you report the force in the usual way?

[rikyfritz95]

Thank you for your answer.

Yes, if I calculate the lift-force in the report definition section Fluent correctly does it. The problem arises when I evaluate the adjoint observable. Here I upload a screenshot of the reported error. After this error Fluent crashes.

 

[DrAmine]

Which version are you using? Have you tried to evaluate something else?

[rikyfritz95]

Yes, if I evaluate other observables like "Pressure-drop" the problem doesn't come. I'm using the Ansys19 version.

 

 

[DrAmine]

Version 19 is old: I am not sure if there were issues in the past. Attach a screenshot of the Adjoint Observable  definition please.

I am now using 2019R3/R2 and there is no issues with the tutorial you are mentioning. Alternative: try doing an observable as surface integral of pressure and wall shear stress.

[rikyfritz95]

Ok, here I attach the screenshots of the observable definition. Differently from the tutorial I don't use the sine and cosine because I have already rotated the airfoil in the geometry with the angle of 1.5°.  

 

[DrAmine]

Check if you can do surface integrals as mentioned

[rikyfritz95]

I have just tried but It doesn't work in any case. Here I attach the error (no such file or directory)

 

It evaluates only the pressure drop observable

 

 

 

[DrAmine]

Okay seems something related to integral based observable. Is it possible to try a newer version?

[rikyfritz95]

Yes, probably the university's computers have a recent version. I will try there. Thanks a lot.

Best regards

[DrAmine]

Welcome.