Problems in Pressure results in HyperMesh CFD

Victor_op

Hello all.

I'm currently trying to simulate a NACA 0012 airfoil, yes, the same as the tutorial one. Instead, I'm simulating in 3D.

I'm pretty sure my mesh is acceptable in order to have coherent results.

I'm using the ''pressure farfield'' boundary condition for the simulation zone and the ''wall'' boundary condition for the 3D airfoil itself.

When comparing results with NASA's validation, I obtain a really low Cp value compared to them and this is due to a poor calculation of the pressure in the wall of the airfoil.

I would like to know why this error can exist, since, I am pretty sure the mesh is well done and the boundary parameters are aswell correct (pressure, x velocity and y velocity).

I'll attach the boundary condition set up and parameters of my simulation:

Thank you so much.

Notice how the minimum pressure obtained should be lower (close to 55000 Pa).

Notice aswell how the pressure vectors are well captured near the wall:

acupro

Let me suggest you look at that validation model (domain sizes, mesh, etc) more closely, as the domain boundaries are much farther from the body than in your model you show. You likely need to refine the airfoil and nearfiled. You need to keep the mesh finer closer to the body - as it gets coarse quite rapidly. Since you have an angle of attack with the incoming velocity, you also need to resolve the wake region in that direction - as the wake will not flow directly to the right in your images - but more at the same angle as the inflow velocity. That is also another reason to make the domain boundaries farther away - to avoid their impact on the region of interest.