>> For simplification, consider 2 physics on the same domain: Consider >> the 3-D heat conduction and a neutron diffusion model (both are >> nonlinear diffusion-reaction equations) which are described over the >> same 3D domain. Now, can I get away with using a single >> EquationSystems object with a single mesh even though the element >> sizes used for different physics could be different ? And since I >> would define 'mesh' to be the representation of the domain using >> different elements, and since the elements used in terms of size and >> type could be different for different physics, these would be >> different meshes. Does that make sense ?
The question makes sense, the motivation does not (to me anyway). > > You basically want to have two (or more) completely unstructured, > overlapping grids with a different variable defined on each one, > if I understand correctly... > > The problem is that it's easier to describe/conceptualize than it is > to implement, at least in a completely general sense, and while in the > LibMesh framework. > > The approaches that Ben described for Taylor-Hood elements where you have > a linear pressure sitting on top of a quadratic velocity field are, > I imagine, too specialized for what you want to do. (Another issue > which arises in these mixed methods is the compatibility of the spaces, > and that can be tricky to work out.) And this is a key point... Loosely coupling two separate systems on different meshes is not too hard and often done in practice. You could, for example, have a temperature field on a tetrahedral discretization of the same space as a hexahedral discretization of a velocity field. Each would give rise to its own implicit system. The only compatiblity you have between the discretizations is the interpolation error you are willing to take when you interpolate the solution of one system as the input data of another. If these truly need to be in the same implicit system, though, I cannot think of *why* you would want to have them on two separate discretizations?? -Ben ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
