I am carrying a very simple 2D transport conservative model (no reaction term), with very high pectle no., so it suppose to be advection/dispersion transport flow. there is one confining vertical layer with 2 openings to mimic a fracture open.
the plume as you can see in the attached figure is not expanding vertically across the mode, as could be expected from such simulation and even in nature (my lab experiment).
could anyone help in this, and what could be the problem in such simple simulation