Simulation converges too fast when cell count is high

Ancientkingg · December 23, 2021, 11:48

I am currently working on a case that uses the simpleFoam solver with the kOmegaSST turbulence model. It involves meshing a car and then running the solver on that mesh. However I seem to notice that when the cell count of the mesh is above a certain level the simulation stops at around timestep 8-10, which I assume is because of convergence. When I lower the cell count in the blockMeshDict and the level of detail in the snappyHexMeshDict the simulation seems to run from start to end.

Would anybody know what could perhaps be the root of this issue?

Tobermory · December 23, 2021, 12:19

I doubt very much that it is because of convergence, since it has only run 8 - 10 iterations. What was the result of checkMesh? Did it crash or end cleanly? Did it post any error messages during the run?

Can I suggest that you post the log from your run, and maybe your fvSolution file? That way, we can take a peek at what is going on. Cheers.

December 23, 2021, 11:48	Simulation converges too fast when cell count is high	#1
Ancientkingg New Member Join Date: Nov 2021 Posts: 1 Rep Power: 0	I am currently working on a case that uses the simpleFoam solver with the kOmegaSST turbulence model. It involves meshing a car and then running the solver on that mesh. However I seem to notice that when the cell count of the mesh is above a certain level the simulation stops at around timestep 8-10, which I assume is because of convergence. When I lower the cell count in the blockMeshDict and the level of detail in the snappyHexMeshDict the simulation seems to run from start to end. Would anybody know what could perhaps be the root of this issue?

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December 23, 2021, 12:19		#2
Tobermory Senior Member Join Date: Apr 2020 Location: UK Posts: 746 Rep Power: 14	I doubt very much that it is because of convergence, since it has only run 8 - 10 iterations. What was the result of checkMesh? Did it crash or end cleanly? Did it post any error messages during the run? Can I suggest that you post the log from your run, and maybe your fvSolution file? That way, we can take a peek at what is going on. Cheers.