Peter Schätzl Grundwassermodellierer

Multilayer wells use discrete features for simulating the flow in the well pipe. Ss of multi-layer wells refers to the specific storage within the pipe.

Thanks for the positive feedback, and have a great weekend, too!

The heat-transfer BC in FEFLOW (used without boundary fluid flow) is is simply heat conduction with a heat transfer coefficient. The theoretical background of FEFLOW is avalailable in the FEFLOW book (https://www.springer.com/de/book/9783642387388) or - with less up-to-date and less revised content - in the older Reference manual (e. .g., https://www.yumpu.com/en/document/read/20781782/reference-manual-feflow).

I'm not sure whether this has been studied in detail yet. I know of a FEFLOW user having simulated a similar situation for sheet-pile walls connected to pipes for heat exchange, but I cannot remember the details of his work. However, I think in any case the procedure will highly depend on the scale of the system and the level of detail required. For a long stretch of diaphragm wall with multiple (parallel?) connections to a heat pump a heat source/sink might be a sufficient solution, with reasonable assumptions about the heat transfer, depending on (seasonal) ground and fluid temperatures. The smaller the scale gets, the more you'll need a spatially correct solution. There the simulation using discrete features may be a good solution. On the other hand, the horizontal slice could be a valid approach, too. If heat storage in the diaphragm wall is negligible (because of the time scale), then you may even be able to derive a bulk thermal resistance between the fluid in the pipe and the interface between the diaphragm wall and the ground - and this could then be applied for a heat-transfer BC.

Many options - and I think you'll have to choose depending on the questions asked to the model and the temporal and spatial scales required.

If the volumes are already perfectly separated, just import at least one point per zone as a point in the supermesh and declare it a 'Region Marker'. With this, TetGen will sort the resulting tets into groups for each zone.

The only way (AFAIK) is to export the cross section as a new DAC file from an existing 3D dac. This can be done by using 'Save as...' or 'Save copy as...'. With the resulting 2D dac, you can do all the exports you typically do for a slice.

Hi,
The most likely reason for this is that your model is set to steady state in Problem Settings.

The selection is stored in a panel 'Selections' that you are not displaying in your example. You have to open this panel.
Density ratio is an elemental property, but typically will be spatially constant all over the model.

FEFLOW's internal unit for in/outflow on top/bottom is m/d (you can find all internal units in the Units section of the help system). Time series are interpreted based on the internal units, thus FEFLOW takes your values as m/d, showing them as mm/a accordingly. So you'll have to convert your time series to m/d. If you have mm/month you'd have to divide by the number of days in the month and multiply by 1000.

I'd recommend to try Triangle as the next step. While Gridbuilder produces more regular meshes, it is also more prone to crashes during mesh generation, especially in case of line add-ins (see help also).