[cfd9999]

Hello,

I am attempting to set up a case with an impinging air jet. I am consistently receiving a related error and warning:

1) ERROR: The temperature is greater than max_temp in calc_temp_fraction.

2) WARNING: Temperature extrapolation error found at...

So far, I have tried refining my mesh and turning on adaptive mesh refinement. Neither one helped The issue may also be with my boundary conditions, but they seem correct.

When I tried reducing the model to a 2D simulation, the errors did go away, but my goal is to run a 3D simulation.

Does anyone have suggestions on fixes I could try? Thank you.

[ksrivast]

Greetings,

Temperature extrapolation warnings and errors could be resulting due to a number of issues. You have varied your grid settings, but we would also recommend lowering your time-steps (max_cfl_limits) to see if the solution is more stable. We have a similar example case available through STUDIO. Please have a look at Examples > Case_setup > General > Impinging_gas_jet_steady_RANS. Consider adopting the example case settings, if you haven't tried that already.

If you continue to see these issues, we would need to get a better idea on what might be happening by looking closely at the time.out and converge.log files. Are you seeing frequent recoveries during the simulation? What kind of recoveries (max_pstar, max_turbulence, temperature_extrap, etc)? Based on the type of recoveries we can improve the solver settings for the case.

It is also helpful to select log_level=3 in inputs.in. This will print (v3.0 and above versions) the XYZ location(s) of the cells with temperature extrapolation issues in the converge.log file. You can then look at the geometry/post files at such locations to evaluate local cell sizes, or solutions at that location.

Hope this helps. If not, please reach out to us at support@convergecfd.com. Please use your official email for all correspondence with Convergent Science. Please mention your request, attach your case setup and add the cfd-online thread, as reference.

Sincerely,