Pressure Oscilations NACA 0012 Transonic
 

Good Afternoon

I'm simulating some NACA at transonic speeds and when I extract the pressure and pressure coefficients from the wall it's possible to visualize some fluctuations on the pressure plots.

I tried to use first and second order squemes, with different courant numbers but the problem still there. In some subsonic simulations I can see this fluctuations too.

Is there anyone who knows how to correct this fluctuations ?

Some data of my simulation (transonic one) are:
SST K-w
Mach 0,8
Second order and first order upwind (tried them both)

thanks.

Hello,
I have had the same problem, I could only diminish the magnitude of the oscillations, but could never get rid of it, by preparing a fine boundary layer grid. Did you also use Icem CFD and construct a block-structured mesh?

Yes I'm using ICEM CFD. And my mesh is structured.

The first cell is 0.0001 m from the airfoil wall. I checked the y+ and it is around 3 for the airfoil. What's your y+ ?

I solved my problem by setting the tri tolerance to 10E-7 from 10E-3 (Settings->Model->triangulation) My y+ value is around 1 because I am using enhanced wall treatment. It depends on the wall function.

so it is the mesh that matters at last? i mean the oscillation of pressure coefficient