Hello out there,
I have a problem in modeling the expansion of saltwater... first to my modell (feflow5.2):
I have time controlled disposal wells, without any casing, so the screen is about 300 m through seven slices of my model. In the Flow-boundaries I put the injection-rate (via timecurve xy) in slice 1, all other slices have a well at that special node, but without any injection rate.... I do use well bore conditions, so the well is linked and the flow is functional in all slices...
so far
but now I want to update this model for [b]transport of saltwater[/b]... In the problem class I`ve choosen "flow and mass transport", "single species", so my Species is NaCl....
I´ve entered a background or better an initial concentration of about 13000 mg/l (this area is outside europe, the values are save, believe me) for the whole model area, one border is a coastline, there i`ve put an average value of 45000 mg/l...
now for the disposal wells I have checked serveral different input methods and alternatives. first of all the water injected to the aquifer has a TDS of about 150000 mg/l, so the concentration should rise and rise and rise in the ambience of the wells but what happens: from slice 3 to 7 there is a negative concentration given after the run (-12000 mg/l for example)... in one slice (sl2) there is a little positive fringe, showing that some of the high concentration water is really injected, but in all layers below the concentration is < 0 mg/l !!??? ... can somebody think of a soultion?? i cannot explain it to myself..... i would think the high-concentrated water should sink through the aquifer, shouldn´t it? by the way, this should be the aim of my model, showing where the flowpaths are going from this injection points... but density- and concentration-coupled...
or somebody knows a tutorial 'bout that? [move]gerne auch auf deutsch ;)[/move]
regards!
AL
