• Re: How to define temporal BC in Expression Editor

    thanks for the answer. This should work, of course, as well as I can create second time serie according to the recorded temperatures on the known node, but what I would like to do, is set the Temperature BC on any node just using editor in transient mode. So the temperature on the node (111) is changing during the time. If I write: Current = T(111)@(Time) + 5, the temperature of my node is in the initial time really 5 K higher, but in next time steps this difference is not preserved. There is no change in simulation, if I write: Current = T(111)@(Time) + 5 or if i write: Current = T(111)@(0) + 5. So the question should probably be: can I define the Time as variable?
  • How to define temporal BC in Expression Editor

    Hi to all,
    I would like to define Temperature BC at node in transient model. This temperature should be 5 K higher than the temperature at some other node.
    For example: Node Nr. 111 lies inside an area, where is the GW temperature seasonally changing. At node of my interest, I would like to have temperature 5K higher, than at node Nr. 111 during the whole simulation period. In Expression Editor this...  Current = T(111)@(Time)  ... does not work.

    Is there any way how to simple define this?
    Thanks in advance.
  • When and why are conductivities of two neighboring layers too different?

    Dear Feflow Masters,
    I am trying to simulate a water-table of an area with two layer model, where the lower layer represents tertiary clays (kf 10-7 m/s) and the upper one gravel/sand (kf about 10-3 m/s). The model is set as steady, with unconfined aquifer and unconstrained head. The border conditions (Hydraulic Head and Fluid-Transfer) are defined above the clay (in upper layer).  The lower layer is wavy with relatively steep slopes and I am not able to reach stable simulation. Is this caused by dry cells? I tried to reduce residual water depth to avoid errors in flow directions, as well as the Inflow on the top layer, without any progress. Likewise the vertical refinement of mesh does not lead to any improvement.
    Thank you very much for any tips.
    PS: for Kf 10-3 m/s for upper and 10-6 m/s for lower layer works the model fine. But the lower layer has to be less conductive.