Learning Forum

[Osama1998]

Hello Im using ansys 2020 R2 , Im modelling Naca 0012 at 0 AOA I got good results cd 0.0062 and cl 0.00007 , which is good, but when I canged the AOA to 3 degrees from the inlet velocity , I setit to "magnitude and direction" my manitude is the same 43.8 , x- component is sin3 and y component is -cos3 , I got very bad results CD went to 0.0011 and CL 0.17 which not logical or accurate, what can I be doing wrong.

[Rob]

If you plot the velocity how does it look?

[Osama1998]

velocity residuals seem to be smooth
Is this what you meant?

[Rob]

No, the velocity vector plot. We can use that to check the flow is going where you think it is.

[Amine Ben Hadj Ali]

You can use dynamic mesh for that. Save case file first. Then Enable Dynamic Mesh (after you switch to transient), Under your cell zone add mesh motion and provide Rotational Speed and direction of rotation, In dynamic mesh panel run single time step a 1 second to rotate the mesh by previewing mesh motion. Save new case after you switch off dynamic mesh and transient. Other idea is to create Fluent Expressions where you incorporate the AoA in your velocity profile prescription!

[Amine Ben Hadj Ali]

Your question title has nothing to do with the problem you are describing by the way!