Transient In/outflow on top/bottom

Hi,

I have a bunch of timeseries representing recharge across my model domain... However, I don't know if it's working properly since it doesn't show any information on whether it's been assigned the timeseries properly. I think this is a new feature; I believe we've normally used flux boundary conditions to represent recharge previously, but I like these in/outflow conditions more. Does it work and am I doing something wrong?

Thanks,

Adam

The assignment of time-varying groundwater recharge as an in/outflow on top/bottom material property follows the same concept like any other material property assignment. Depending on the format/structure/architecture of available data FEFLOW provides a broad variety of possibilities to input these data. A detailed description is provided by the FEFLOW Help => Contents => How to => Model Setup => Assignment of Time-Varying Material Properties.

If you want to check whether or not time-varying recharge is assigned properly FEFLOW provides the option to browse through the periods in the legend. Please note, that FEFLOW does not update time-varying material properties graphically while you are simulating. However, there is a workaround if you want to co-process the data during the simulation. You could add a Nodal Expression and refer to the time-varying material property of interest (e.g. in/outflow on top/bottom).

Ahh, adding a Nodal Expression represent time-varying material properties sounds perfect! Clever workaround!

Hi There.
When I am trying to apply differing time series (average, wet, dry, monsoon years) to my material property in/outflow my heads are coming out huuuuge!! Like 8000m when in steady state they are between 2-3m.
I am trying to run it for one year using a .pow file like I have attached.
Can anyone pleeeeeease help :)

A good question to ask yourself is how you derived your transient flux. The problem could be that the average of those transient values over the entire transient simulation is different than the steady-state derived flux values. The averaged transient values and the steady-state should be similar if you want to have reasonable heads (typically). This is especially important is smaller-scale models.

Another problem might be that the top of the model is acting like a capillary barrier in unsaturated-saturated flow problems: dry season may lower your hydraulic conductivity so much that you get lots of surface head once you have a wet season.

Another problem might be that the larger fluxes over your model may be too much if your model is a relatively small volume, such that it cannot store all the additional water.

Hope this helps.

Adam