Solution not converging

Alex

Hello Fluent users,

I am analysing 2D airfoil flow at Re = 1 million. When I was using fully turbulent models such as k-e and k-w models the convergence is good but the Cl and Cd results are higher than the experimental results (around 30 % error).

Since I know the transition point I divided the domain into two and assigned fluid zone before the transition as laminar and after the transition point as turbulent.

When I select the laminar zone in the fluid (before transition point) boundary condition my solution is not converging and the residuals are oscillating like small waves especially continuity and epsilon. But the Cd and Cl values are stabilized and close to the experimental values.

Currently I am using realizable k-e model with enhanced wall function and using quick discretization schemes.

I am looking forward for someones advice.

Cheers, Alex