Denim Umeshkumar Anajwala

Unless you look at very local effects, it is sufficient to consider the screened interval of the well. As the conductivity in the open pipe is very high compared to the aquifer, the head difference within the well pipe will be very small. thus the vertical location of the pump (FEFLOW assumes the lowest node) is typically not crucial. If for some reasons you think it might be, you can do a comparison by using a Well BC plus discrete features for the well instead of a multilayer well. Technically this is identical, but you can place the Well BC in any node you want.

Blair,

I don't think that there are general issues with imbalance, but the solution of course gets more difficult in the phreatic case due to potentially large parameter contrasts. I'd recommend to turn on the error norm visualization (in the context menu of the User Data section in the Data panel) to see whether there are regions in the model with a large remaining error. Having idenified those, you might have a better insight into potential solutions.

Good luck!
Peter

There's no general answer to this question, and maybe we should also add the fully unsaturated solution as the third option. You may refer to the corresponding chapters in the FEFLOW User Manual to get information on the advantages and disadvantages of the three options for specific application cases.

Michael,
the most crucial condition for mesh generation for unstructured geometries is that there are no overlaps or intersections of any elements in the DXF or 3DS file. We don't have much exerperience with Surpac yet, but such overlaps or intersections are very common in output of other geological modelling software (as for visualization clean geometry is not a condition). This, however, should not be the case for the 3D Studio Max output of a simple sphere. Could you send me the 3ds file of the sphere  (psc@dhigroup.com)? I'ld like to check it myself. I've run a large number of tests with simple geometries created in SketchUp and Blender (to test their intersection capabilities), and simple geometry 3ds output worked fine for meshing in FEFLOW.

Best regards,
Peter

In many such cases a larger model area would be a good idea, at least if the outflow occurs in the same aquifer the river is in. Putting a boundary condition below the river can of course produce a model outflow, but - no matter what the BC is - most probably not reflect the natural conditions very well. For example, the aquifer on the other river side in reality will contribute to storage etc., and you cannot consider this by just putting a BC. As a personal opinion I think that groundwater models are way too often cut off at rivers as assumed natural boundaries, while in reality there is significant flow across the river in the aquifer below, and the conditions on both sides of the river influence the groundwater conditions. 

Hi,
The file looks OK at least at first glance. Did you check the properties of the Observation Point in the corresponding dialog after import to make sure the import worked well?
Peter

The expressions can currently only be used to assign values to a BC, not as expressions that are evaluated during run time. This is only possible for the recharge and source/sink parameters (flow and transport). If this is about an open-loop geothermal system, where the injection temperature is 5K different from the extraction temperature, the FEFLOW support team can provide you with a free plug-in achieving this (OpenLoop). If it is nodes other than pumping wells, you'd have to program your own plug-in or python script.

Well, I just received an answer from WASY. FEFLow 6.211 (p11) works better witn VS 2013.

Hi.

Anyone knows which version of Visual Studio is compatible with FEFLow 6.2 (p11) to write plug-ins?

Thanks in advance.

FEFLOW uses the concept of an 'equivalent freshwater head' where the hydraulic head is expressed in terms of an equivalent head at freshwater conditions. Thus in case of saline groundwater, hydrostatic conditions result in an equivalent freshwater head that increases linearly with depth. The same concept has to be applied to initial head throughout the model domain. So in FEFLOW 'head' never means 'saltwater head' but always 'equivalent freshwater head'.