The desire to simulate even more geometrical and physical features of technical structures and the availability of parallel computers and parallel numerical solvers which can exploit the power of these machines have led to a steady increase in the number of the grid elements used. Memory requirements and computational time are too large for usual serial PCs. An a priori partitioning algorithm for the parallel generation of 3D non-overlapping compatible unstructured meshes based on a CAD surface description is presented in this paper. Emphasis is placed on practical issues and implementation rather than on theoretical complexity. In order to achieve robustness of the algorithm with respect to the geometrical shape of the structure, the authors propose that there should be several or many but relatively simple algorithmic steps. The geometrical domain decomposition approach has been applied. It allows us to use standard 2D and 3D high-quality Delaunay mesh generators for independent and simultaneous volume meshing. Different aspects of load balancing methods are also explored in the paper. The MPI library and SPMD model are used for parallel grid generator implementation. Several 3D examples are given.

An algorithm for the automatic parallel generation of three-dimensional unstructured grids based on geometric domain decomposition is proposed. A software package based on this algorithm is described. Examples of generating meshes for some application problems on a multiprocessor computer are presented. It is shown that the parallel algorithm can significantly ( by a factor of several tens) reduce the mesh generation time. Moreover, it can easily generate meshes with as many as 5 x 10(7) elements, which can hardly be generated sequentially. Issues concerning the speedup and the improvement of the efficiency of the computations and of the quality of the resulting meshes are discussed