• Re: "fixed" slice question

    I would like to add to this post (if I may).  I understand that layers below fixed slices remain saturated, but after running a model that has a moveable surface above a series of fixed slices, with boundary conditions assigned to lower layers (eg wells, or similar) that should desaturate shallower layers, the simulated pressures can be negative (i.e. unsaturated).  Is this because pressure is simple calculated after the simulation (Head = elevation + pressure head, rearranged of course)?  Does this also mean that with a fixed slice, although a simulated head may be below a layer base elevation, Feflow (in simple terms) uses the Transmissivity based on the assigned aquifer thickness and hydraulic conductivity, the specific storage (ignores storativity) and the gradient (regardless of whether the actual elevations are above or below the assigned slice elevations) to simulate the overall result?  And as a result there will always be flow, even when simulated heads are below the based on the assigned slice elevation (when assigned as fixed).
  • Axisymmetric 2D models in FeFlow

    Can someone tell me what angle is used in the axisymmetric formulation of a 2D model in Feflow.  is it 1 degree (or something else).

  • Re: Wells in a moving mesh model

    Yes I undersand, and thanks again for the answer.  One last question to finish this one for me.  I am guessing with the free surface moving slice option, all boundary conditions will move if the the slice that the bc is on moves.  That is, the bc is slice related and not aligned with the geological layering defined in the 3D slice elevation menu.
  • Re: Wells in a moving mesh model

    Thanks Peter. Is this the correct forum to ask why the well bc does not simply place a zero pumping rate if the head is at or below the constrained minimum head, regardless of how this happens?
  • Wells in a moving mesh model

    I have used a well boundry condition in a moving mesh 3D saturated groundwater flow model and the
    boundary condition is only applied across the layer that is considered the aquifer.  If I now apply a pumping rate that results in a groundwater level that is below the base of the aquifer (i.e. solves an groundwater level that is below the original base of the well boundary condition), will the  simulation continue.  If it does I am guessing that the slices that were originally within the aquifer layer will now be in a layer belwo the aquifer. 
    I assume if this is the case, to stop this from happneing I could constrain the use of the well boundary condition such that the level can not go below a predefined base of aquifer elevation.  Is this correct?