Dear Martin, Attached you can find the corresponding files. Additionally, I forgot to tell you that I am now using Neumann no-flow boundaries at all boundaries. Thank you in advance and if you need further data, just let me know.
Best Regards Sebastian Von: Martin Schneider <[email protected]> Gesendet: Dienstag, 14. September 2021 09:15 An: Alexander Sebastian Hogeweg <[email protected]>; [email protected] Betreff: Re: AW: AW: [DuMux] Heterogeneous cornerpoint grid - Pressure drop/increase in scattered cells Dear Sebastian, could you please also provide the header files of your test case. It would help to see the boundary conditions, etc. Best regards, Martin On 14.09.21 08:36, Alexander Sebastian Hogeweg wrote: Dear Martin, First of all, thank you again for your time. Now, I built a 1p (liquid) cornerpoint model to find the origin of the problem. However, now I am observing a pressure change in the complete structure. The attached images represent the pressure initially and after the first timestep (100s). The initialization is done using the hydrostatic pressure (simpleH2O): values[0] = globalPos[2] * 1000 * gravity()[2]; The petrophysical properties are defined as homogeneous (k=1mD, phi = 0.2). The structure's thickness is approximately 190m which should induce a pressure difference of ca. 19 bar along with the structure. After the first time step, the pressure difference increases to 66bar, which I do not understand. Do you have any ideas about what is causing this problem? Thank you in advance. Best regards, Sebastian Von: Martin Schneider <[email protected]><mailto:[email protected]> Gesendet: Freitag, 3. September 2021 11:43 An: Alexander Sebastian Hogeweg <[email protected]><mailto:[email protected]>; [email protected]<mailto:[email protected]> Betreff: Re: AW: [DuMux] Heterogeneous cornerpoint grid - Pressure drop/increase in scattered cells Dear Sebastian, I just checked the tpfa darcylaw: https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/-/blob/master/dumux/flux/cctpfa/darcyslaw.hh and it seems that you can't use my previous suggestion and simply use absolute values in the functions of https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/-/blob/master/dumux/discretization/cellcentered/tpfa/computetransmissibility.hh because there in the darcylaw we calculate the transbissibility t_j related to the neighboring element as: -1.0*computeTpfaTransmissibility(....) Did you try to change https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/-/blob/master/dumux/flux/cctpfa/darcyslaw.hh such that all transmissibilities for the flux calculation are positive. Maybe you could also start setting up a 1p problem and try if it works there. Best regards, Martin On 03.09.21 11:11, Alexander Sebastian Hogeweg wrote: Dear Martin, thank you for the fast response. I followed your recommendations and changed the cell center location based on the arithmetic mean (HACK_CELL_CENTROIDS). Here, I am still facing negative values for the grid block transmissibilities (ti). Additionally, I use the absolute value for the transmissibilities leading to positive values. However, the pressure drop/increase in some cells is still observable. Do you have other ideas, which could cause this behavior? Thank you in advance. Best regards, Sebastian Von: Martin Schneider <[email protected]><mailto:[email protected]> Gesendet: Freitag, 3. September 2021 09:37 An: DuMux User Mailing List <[email protected]><mailto:[email protected]>; Alexander Sebastian Hogeweg <[email protected]><mailto:[email protected]> Betreff: Re: [DuMux] Heterogeneous cornerpoint grid - Pressure drop/increase in scattered cells Dear Sebastian, for CP-grids it might happen that the centroid is located out of the cell such that the currently implemented transmissibility calculation yields negative values. Did you check if all the transmissibility calculated with the functions in the following header https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/-/blob/master/dumux/discretization/cellcentered/tpfa/computetransmissibility.hh are positive? I guess you will observe negative values. There are two solutions to overcome this 1. Try to use another cell center instead of the centroid. 2. Try to use the absolute value of the transmissibility (corresponds to switching the normal vector of the corresponding face) I hope this solves your problem. Best regards, Martin On 02.09.21 18:15, Alexander Sebastian Hogeweg wrote: Hello everyone, I am facing a problem during the simulation of an underground gas storage scenario. The used grid is a cornerpoint-grid with a heterogeneous distribution of permeability and porosity. Additionally, the structure contains a fault connecting a lower part of the formation. The used fluid model is 2pnc (h2on2o2), and the initialization is based on the example 2p_cornerpoint (hydrostatic pressure and pores fully water-saturated). At the top and bottom of the structure, Neumann (no-flow) boundaries are defined (Dirichlet at the sides with initial). In the present status, the molecular diffusion is deactivated, and additionally, the centroid cell center location is used. After the initialization (looks all right), the pressure in some cells of the lower part increases while neighboring grid blocks show a lower pressure. Attached you can find some images showing the problem (Image 1 and 3: t=0; Image 2 and 4: t =6000s (timestep 8) and the problem file. Other (more conforming) cornerpoint-grids do not show this behavior. Overall, I would like to know if somebody else observed a similar situation and could help me with the problem. I appreciate any help you can provide, and please let me know if you need further information. Best Regards, Sebastian Dumux Version: 3.4 Model: 2pnc Grid type: Cornerpoint Fluid system: h2on2o2.hh _______________________________________________ DuMux mailing list [email protected]<mailto:[email protected]> https://listserv.uni-stuttgart.de/mailman/listinfo/dumux
properties.hh
Description: properties.hh
spatialparams.hh
Description: spatialparams.hh
problem.hh
Description: problem.hh
params.input
Description: params.input
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