Dear Etienne Ahusborde, Sorry for the last email, and I wish you an excellent new year.
I only tested Mandel’s problem using coupled and fixed-stress methods and got similar results. Both methods show the same error. Maybe it is related to the different discretizations. The main concern is whether the two methods return the same results and if one can benefit in terms of computational efficiency. In the fixed-stress method, the two subproblems are implicitly solved and exchange porosity(el->2p) and effectivePorepressure (2p->el) in each iteration. However, less attention is paid to discretization. Porosity is evaluated at the cell center, while the constant pore pressure in each subcontrol volume is identical to that of the corresponding element in the flow problem. No additional interpolation is performed. Regarding the convergence problem, did you try the initial run (constant pore pressure) for initial displacement in your simulation, or how do you handle your initial values in the poromech problem when the Neumann boundary condition is set? Best regards, Yue Wang ******************************************************** Yue Wang Universitaet Stuttgart Institut fuer Wasser- und Umweltsystemmodellierung Lehrstuhl fuer Hydromechanik und Hydrosystemmodellierung Pfaffenwaldring 61, 70569 Stuttgart Tel.: 0711/685-64899 [email protected]<mailto:[email protected]> https://www.iws.uni-stuttgart.de/lh2/ ******************************************************** On 5. Jan 2023, at 14:42, Etienne Ahusborde <[email protected]<mailto:[email protected]>> wrote: Dear Dumux community, First, we wish you an happy new year. Since our last questions about flow and poromechanical coupling on Mandel problem, thanks to the help of Yue Wang, we have been able to perform simulations by using the coupling manager for fully implicit approach and we greatly thank you for that. Then we tried to reproduce in version 3.5 the test case « 4.2 CO2 injection heterogeneous » proposed by Beck in Accuracy of fully coupled and sequential approaches for modeling hydro- and geomechanical processes, Computational Geosciences (2020) 24:1707–1723. We used the implicit model el2p from multidomain example. We looked in details the source of the code in version 2.12 but when we tried to consider the same boundary conditions in version 3.5, we obtain some convergence issues. The only solution to reach solver convergence is to impose Dirichlet conditions on all boundaries for all displacements but results are obviously different. Has somebody already tried to perform this case in a recent version of DUMUX? Moreover, we would like to compare the results using implicit and sequential approach by using a fixed stress scheme where the two sub-problems (flow and poromechanics) are decoupled and solved sequentially. Unfortunately we are facing some difficulties on how to set up communications between the two sub-problems. Like the flow problem is solved with a cell-centered scheme, we need to extrapolate the pressure in order to express it from cell to vertex. This is necessary to pass it as argument to the poromechanics problem which is formulated with the box method (vertex). The same problem occur in the other direction, from poromechanical problem to flow problem where an interpolation is necessary to pass from vertex data to cell data. Are there some existing tools in DUMUX to make some conversions in a simple way ? Thank you for your answer Best regards _______________________________________________ DuMux mailing list [email protected]<mailto:[email protected]> https://listserv.uni-stuttgart.de/mailman/listinfo/dumux
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