[johny_walker]

Lets say I have a mesh of 130,000 cells which works fine with courant number of 200. Next we have a 180,000 cells which shows wave like pattern in Cl and residuals vs iteration plot with courant number 200 however works fine with courant number of 20.

So for grid independence study, is it necessary for us to simulate the mesh with 130,000 cells again with courant number 20 since we got a stable result with this courant number for 180,000 mesh.

Basically I want to know that does Courant number affect the flow result or is it just used to see faster convergence? Also, can we do grid independence study on different meshes with different courant number or courant number should be same for all the meshes to perform grid independence study?



P.S. I am simulating an external air flow over windsor model in Ansys Fluent using k-omega sst model in 2d.