A scalable, robust parallel algorithm on handling of sliding non-conformal interfaces with an efficient supermesh method

Abstract

Handling of non-conformal interfaces communication is one of the challenges from which the parallelization of multi-zone unstructured grids technology suffers. Especially for dynamic mesh simulation, changing dynamic communication patterns induced by the grids relative motion requires data to be correctly transferred across discrete non-conformal interfaces at every time step. To overcome the challenges at extreme scales in this paper we attempt to design the parallel algorithm in such a way that it enhances the scalability of the sliding mesh method implemented in the simulation of practical engineering problems with complex geometries. In the proposed parallel algorithm, the issue of changing dynamic interface communication is handled by a scalable and robust parallel supermeshing algorithm which has no constraints on the domain partition schemes and is adapted to complex practical engineering simulation. Besides, a unified cell-based communication map adapting to parallelized matrixes solvers is dynamically reconstructed by assembling both the inner-boundary communication map and interface communication map, which greatly improves the robustness and scalability of the sliding mesh algorithm executed on the parallel CFD code. All methodologies are integrated and implemented for parallel computation obtaining good scalability and computational efficiency. Specific examples are solved to analyze the conservation, scalability and robustness of the parallelized interface approach and finally, the full-cycle unsteady simulation of a four-stroke engine is tested to evaluate the performance of this parallel strategy when applied to practical engineering problems.