Does anyone have any advice on this problem?! :(
I'm simulating a contaminant plume and can't seem to avoid oscillations and negatives in the concentrations at the edges of the plume. The mesh was set up to maintain a Peclet number of less than 1 given the dispersivity, so I don't think that refining the mesh will help. I also ensured it had <5% obtuse triangles. I've tried different upwinding techniques, but none of those remove the problem entirely either. I've also tried a more gradual introduction of contaminant over time, but as soon as any contaminant mass enters the system then the negative values appear...
Would be really great if anyone can help!
Thanks,
Gemma
