run option - transient transport

Hi there,
I am wondering if "transient transport" can be run separately from a flow model run. In another word, to run a transient flow first, then save the simulation results of the end of the flow model run, and then run a transient transport on top of this "fixed" flow regime. I noticed there are three options for running a "flow and mass transport" model in FEFLOW, i.e. (1)steady flow/steady transport; (2) steady flow/transient transport; and (3) transient flow/transient transport. So, there are two options available for transient transport, i.e. options (2) and (3). I tried to use option (3) transient flow/transient transport to simulate; however, it took too much time to run. So, I am wondering if there is a way I can use the end results of a flow model run (transient), and run transient transport only on top of this simulated flow regime in stead of using option (2)- steady flow/transient transport. I remember Visual Modflow allows you to run flow and transport separately.

Thank you very much in advance!

b

FEFLOW does not provide the option to run flow and transport separately - you always have to do both simultions at the same time. This is necessary for density-depentent simulations, where the transport solution feeds back into the flow calculation.

It would be nice to be enable reuse of a transient flow field for uncoupled problems, especially in cases where flow field takes a long time to solve.

Hi there,

Still no way to load flow fields from previous simulations to simulate new transport problems?

I am simulating groundwater flow with salinity-dependent density. I am working over large periods (several thousands of years) so I use large time-steps and select the fully implicit time-scheme. The model runs ok, within a couple of days.
Now I would like to add another transport problem (some very simple conservative transport, for tracing). Since Feflow only provides automatic time-stepping for multispecies problems (I would be happy to know why), I can't use the implicit time-scheme anymore. I am looking for alternative options, like e.g. loading flow fields into new simulations. Any idea?

Arnaud

The concept in FEFLOW is still the same: flow and transport are always solved in parallel, so there is no option to load a flow solution and run transport on this basis.