To 'couple' or not to 'couple'...)
 

Hi Folks!

I have an easy doubt. I have an air flow at a rate of 90.3m/s (that is M=0.266, still <0.3, so I solve the problem by means of the segregated solver), smashing a 3D rectangular wall. I want to get the pressure distribution over the wall.

But the problem comes when I solve the problem with the segregated solver (convergence in 2nd order QUICK is fine) and I found that in certain locations of the wall, the air goes at a speed of 170m/s, that is M=0.53, which is more than the threshold of 0.3 which shows us if we need to switch to couple solver, due to the flow must to be considered compressible.

The question is: if the mean flow is M<0.3 but in some little locations (corners of the wall) M>0.3, may I use coupled or segregated is still valid??

Thanks to your opinions

Regards,

Freeman