Dear Friends,

In CFX, which model is better for calculate high speed(M =1), compressible air? K-e model??

Thank you in advance.

Eric

SST

Thank you.

And which is better, upwind or high resolution?

Thank you in advance

Hi Eric,

about upwind: it is more robust, needs less computaional time and is less accurate...

on the other hand, about high resolution: it is less robust, needs more computaional time, is more accurate and also need finer grid size...

so, you have to decide, which on fits to your problem more!!

Best regards, houman

Many Thanks

Just the opposite: high res, being more accurate (mostly second order rather than first order), actually requires a less fine mesh than upwind in order to achieve a mesh-independent solution.

High res is also (generally) quite robust - it is the default!

In general, avoid upwind.

I agree with Phil. Only use upwind to get a solution started. Always switch to high res for final solution.

Johnny is right

Upwind = You are more likely to get a "conservation satisfying" answer but it is wrong.