Dear Sir/Madam,
We are developing a semi-structured code based on a triangular mesh. It has similarities to Adaptive Mesh refinement (AMR) in which from an initial mesh (in our case unstructured) a structured mesh is generated based on a refine-by-splitting strategy, ending up, like in AMR, with a semi-structured mesh. * Effectively we need a CSR type storage for the coarse initial mesh and a stencil-based storage for the internal, structured mesh. We have noticed that you have some routines to deal with semi-structured meshes but they specifically target AMR type meshes, which may not be useful in our case as the stencil and neighbouring are different to that of a structured grid-based mesh. Do you think these approaches could be used directly for our case or with minor modifications? * Other possibilities that we have considered are the use of block-structured solvers, however, in our case, the blocks are not dense and therefore this approach will be worse. * Another alternative would be to develop our own multigrid based on PETSc ensuring that there is communication between the different blocks during the smoothing operation, could this also easily be done or would effectively require applying the smoothers independently to the different structured sections and us performing the communication and extra-smoothing steps at the interface? Kind regards, -- Amin Nadimy Applied Modelling and Computation Group (AMCG), Imperial College London
