Hello again, Sam,
IMO the mesh has some room for improvement (well, it always does ). You have a bunch of cells with high non orthogonality, as per the meshing log:
And another potentially worse issue is not having enough refinement in the pollutant inlet patches. If you pay close attention, the faces are not captured smoothly, which could cause some convergence issues/wrong results:
Despite these remarks, I tried to run some simulations with tweaked numerics (some variations of limited schemes, different URF) but all of them were giving unphysical results.
I got a simulation running right now using limited schemes for gradient/laplacian terms and also non orthogonality correctors. I’ll let you know tomorrow if this was enough to prevent the simulation from diverging. It’s looking good so far
Edit: this was the run https://www.simscale.com/workbench/?pid=8374857046360727853&mi=run%3A10%2Csimulation%3A1&mt=SIMULATION_RUN. It ran for 1k iterations, which wasn’t enough to reach convergence just yet (see the area average result control), but it’s safe to say this numerics set works nicely for this specific mesh. Feel free to copy the numerics and try it in your project.
PS: Following Jousef’s hint, I also changed the pollutant source approach from velocity inlet to volumetric sources. Today, when I was inspecting the results, I noticed that I skipped one of the inlets by mistake If you decide to use volumetric sources aswell, doublecheck that you have one geometry primitive for each of the inlets