Acoustic Module
 

Hi. I'm trying to obtain acoustic predictions using a 2D-airfoil. The FW-H acoustic module is giving strange results: relaxation factors have important effects on the sound pressure level (after FFT), producing less SPL for a positive angle of attack than for 0 degrees. Do you have experience using the acoustic module? Have you ever seen the same problem? Sorry, I'm applying CFD for first time and maybe my questions (and my horrible English) are stupid.

Thank you for your help.