[ranxiaoran]

Hello everyone! When I used the one-step hydrogen-air mechanism from the Fluent2021, The results is converged. But when I changed the mechanism to multi-steps mechanism(by hitting ‘Import CHEMKIN Mechanism’ item) from the paper, the residuals became very large, I cannot make it converge.

By the way, I use the density-based solver and calculate the supersonic fluid. I have already used the first order upwind in every items of the Spatial Discretization and the Under-Relaxation factors is 0.1. I use the no combustion fieid as the initial field to calculate the combustion case.

I want to know what cause these problems and how to solve the converge problem.

The attachments are CHEMKIN files and the picture of residuals.
Thank you in advance.