[beanlee999]

Dear all,

I am trying to do a hypersonic flow simulation over a sphere of 0.3m radius. Does Fluent has any tutorials or guides regarding setup conditions for hypersonic simulations?

My simulation Mach number is 22. I am using volumetric (species and transport). The mixture comprises of NO,N,O,O2,N2. I set piecewise polynomial for the Cp of each constituent. My operating pressure is 0. My underrelaxation factor is 0.3 and courant number is 0.3. My temperature limit is set to 24000K. The solver is set to second order upwind.

However, my residual level for either NO,O or N is always rather high. It can be as high as 10e12. Does anyone has any idea what is wrong? Pls kindly help to point out my mistakes... I tried to increase the positivity rate limit to between 25 and 30. The residual level drops a lot to around 10e2, but solution does not converge. Should I have taken this approach as well?

Thank you.