simulated for three cycles of ASR operation and a transient flow is performed for the
length of 168.774 days (Total operation time). The total simulation time for the numerical
model was about ten minutes while it takes less than one minute to run the FORTRAN
code for a one-layer model.
Figure 3-9 shows the position of the front and contour map of the concentration
field with the natural gradient of 0.01 at time=18.55 days, which is close to the end of
recovery phase in the first cycle. This figure may be compared to Figure 3-8 of the
analytical model.
1mmmmmm -_-_-:
mmmm --mmmmmm
mm m m m mm m -_----..m m m mm m m m m
Figure 3-9. The front position at time=18.55 days.
Figure 3-10 shows the concentration breakthrough curves at the injection/extraction
well for three different background gradients of 0.1, 0.2, and 0.3 from numerical and
quasi-analytical simulations. The results match showing that quasi-analytical model
performed well. Considering the relatively short execution times required by the quasi-
analytical model, one may be surmised it could serve as a good alternative model to
MODFLOW/MT3DMS for simulating the performance of ASR systems.