Hi Nikolai,
in the facet coupling framework there is actually a way to obtain the insertion index of an element, which would correspond to the index of the element in the gmsh file. However, you gmsh often starts with the index 1 so be careful to subtract this here. In the facet coupling framework the data on which lower-dimensional elements are coupled to which bulk element are obtained directly from the mesh file. This data can be accessed in the grid manager, i.e. by typing gridManager.getEmbeddings(). However, these embeddings are in gmsh indices (as they come from the gmsh file). Thus, the embeddings also provide an interface insertionIndex(const Element&) so that the embeddings can be translated into dune grid indices. So, if you want to obtain an insertion (=gmsh) index of an element, you can do so e.g. in the main file after calling gridManager.init() and obtaining the embeddings. You could for example then set up a vector of apertures in grid indices by converting insertion to grid index and pass this vector to your sub-problem. Kind regars, Dennis ________________________________ Von: Nikolai Andrianov <[email protected]> Gesendet: Donnerstag, 13. Dezember 2018 15:43:11 An: Gläser, Dennis; DuMuX User Forum Betreff: RE: Variable fracture aperture Hi Dennis, Thanks for your feedback! The domain marker in Dumux refers to the number of Physical Line() in gmsh, so you suggest to create a number of Physical Line’s in gmsh so that each of them could be assigned some specific aperture. I actually would like to keep the number of Physical Line’s limited so that each Physical Line could be assigned some other specific parameter, say porosity. However, I would like to be able to change aperture for every low-dimensional fracture element (i.e. there would be several apertures for the same Physical Line). Is there a way to get the original gmsh index of the low-dimensional elements from the GridData object? Thanks, Nikolai From: Gläser, Dennis <[email protected]> Sent: Thursday, December 13, 2018 09:44 To: DuMuX User Forum <[email protected]>; Nikolai Andrianov <[email protected]> Subject: AW: Variable fracture aperture Hi Nikolai, you can have a look at the fracture exercise in the DuMuX course: https://git.iws.uni-stuttgart.de/dumux-repositories/dumux-course/tree/master/exercises/exercise-fractures Therein, we use the Gmsh domain markers to distribute fracture apertures. The explanation would be a bit lengthy and I guess you can find all the information you need within the exercise description. The main concept is to use the GridData object from the GridManager. In the main file of the exercise you can see how this data is retrieved and then passed to the sub-problems and spatial parameters classes. In short words, in Gmsh you can assign an index (domain marker) to each fracture line (2d domain) or fracture surface (3d domain). All elements that lie on the line/surface will then get this domain marker in the mesh file and it is possible to retrieve this again in DuMuX. Rergarding you question of the interface. As for the other parameter interface functions, for the extrusion factor there is also the version with the suffix AtPos(), but there is also the version taking element/scv/elemsol (see fvproblem.hh): template<class ElementSolution> Scalar extrusionFactor(const Element& element, const SubControlVolume& scv, const ElementSolution& elemSol) const {} Note that the element index alone is not enough to distribute your parameters because depending on the grid manager (ALUGrid, UG, ...), the indices might not be equal to the order of the .msh file. You would need the insertion index of the element. The way to go are the domain markers I would say. I hope this helps! Best wishes, Dennis ________________________________ Von: Dumux <[email protected]<mailto:[email protected]>> im Auftrag von Nikolai Andrianov <[email protected]<mailto:[email protected]>> Gesendet: Mittwoch, 12. Dezember 2018 18:40:21 An: DuMuX User Forum Betreff: [DuMuX] Variable fracture aperture Dear DuMuX experts, Please advise what is the best way to assign variable fracture aperture for a multidomain/fracture flow application. I would like to have apertures be pre-computed and read by DuMuX from an external file, so that the fracture apertures correspond to the numbering of fracture elements in the gmsh mesh file. Currently the apertures are read via extrusionAtPos(const GlobalPosition& globalPos) in the fractureproblem.hh. It would be great if I could get not the position of the element’s center as parameter, but say the corresponding SubControlVolume which apparently does have the elementIndex. But how can I do this without modifying dumux/common/fvproblem.hh ? Thanks, Nikolai
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