Generation of block-structured grids in complex computational domains using templates

Abstract

In numerical analysis, the process of grid generation is used to decompose computational domains into finite elements or finite volumes. It is very difficult to generate quality grids for complex computational domains with a good distribution of nodes. This paper presents a concept for computational grid optimization performed by decomposing complex domains into simpler parts on a basis of a decomposition scheme (“template”). Complex boundaries are replaced by a number of simple patches. Special geometric constraints are imposed on the constituents of patches to allow for the same decomposition scheme to be used for a broad variety of boundary shapes. These constraints ensure consistency of the computational domain during positional and dimension changes of structural components. Grid generation is performed in four steps: building of a template, applying the template to particular data, optimization of the position of subvolume components and finally, the grid generation inside subvolumes. We demonstrate our concept using an example of water turbine geometry and compare the quality of the generated numerical grids with respect to the orthogonality criteria.