Peter Schätzl Grundwassermodellierer

You can invert the BC type in order to achieve this: Set a hydraulic head BC with a min flow constraint of the negative pumping rate plus a max flow constraint of 0.

The discrete feature elements will lead to an increased flow velocity at the nodes shared with the 3D mesh. In detail depending on the velocity interpolation used in FEFLOW, typically the tracks will not run IN the DF, but parallel to them in the matrix elements. This means that their tracks are approximately OK, but flow times will not be (as they are based on matrix properties).

I might be wrong, but I think the situation is even more confusing: To my knowledge, the C++ API functions are still called as written in my earlier post, while the (newer) Python functions are named as cited by Assaf.

dir(ifm.Enum) gives you all the constants, then I filtered by a number of search strings.

I've also had a look through all parameters in ifm.Enum... with the same result: The only auxiliary parameters I can find are P_AUXDIST_E and P_AUXDIST_N which seem to refer to sayer thickness and slice distance. Maybe someoniein support could confirm with dev that the others are not accessible?

Hi Assaf,

I haven't yet used it myself, but the What's new chapter of the help in FEFLOW 7.4 says:

"Through the generalized method doc.getParameter(), we offer a comfortable methodology to access new parameters such as:
    Auxiliary parameters
    Modulation functions"

So with the latest version there seems to be a possibilty. In C/C++ it would be IfmGetParameter() then.

Cheers,
Peter

I think you also deserve an explanation for why the pure use of an in-transfer rate of 0 does not work. AFAIK the flow direction as the basis for the decision on the transfer rate is determined before a steady-state solution (from initials) or before a time step. Flow conditions, however, can change over the step and there is no internal iteration to correct for the use of the in or out transfer rate in this case. The second reason for this not working can be a change in flow direction in between two nodes of the drain. The transfer rates are an elemental property, and thus the in/out decision is made on an elemental level. Nevertheless the BC is on nodes, so if on average for an element the nodes show an outflow, for this element the out-transfer rate will be used when assembling the equation system. Thus a node that has inflow into the model may be assigned an out-transfer rate.

You might have to look up the concept of "suction pressure" - it is perfectly OK to have negative pressure above the water table.

Avec plaisir !

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