Two-level virtual mesh refinement algorithm in a parallelized DSMC Code using unstructured grids

• Published in: Computers & fluids 2011-09, Vol.48 (1), p.113-124
• Main Authors: Su, C.C., Tseng, K.C., Wu, J.S., Cave, H.M., Jermy, M.C., Lian, Y.Y.
• Format: Article
• Language: English
• Subjects: Algorithms; Applied sciences; Compressible flows; shock and detonation phenomena; Computation; Computational fluid dynamics; Computational methods in fluid dynamics; Computer simulation; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Finite element method; Fluid dynamics; Fundamental areas of phenomenology (including applications); Furnaces. Firing chambers. Burners; Gaseous fuel burners and combustion chambers; Monte Carlo methods; Parallel direct simulation Monte Carlo; Parallel processing; Physics; Sampling; Supersonic and hypersonic flows; Unstructured grid; Virtual mesh refinement
• ISSN: 0045-7930; 1879-0747
• DOI: 10.1016/j.compfluid.2011.04.002

In this paper, a virtual mesh refinement (VMR) algorithm for unstructured grids is developed and verified in the parallelized direct simulation Monte Carlo code (PDSC). This algorithm is a two-level virtual mesh refinement, in which the background mesh is refined based on an initial DSMC simulation. The refined cells are arranged in a way similar to the structured grid, which makes the particle tracing on them very efficient, unlike unstructured grids. These virtual cells are used for particle collision and sampling. Only those refined cells which contain the centroid of background cells are used for outputting macroscopic data. Two hypersonic flows with purely quadrilateral and mixed triangular–quadrilateral mesh were used to verify this new mesh-refining algorithm. Results show that the case using VMR can faithfully reproduce the benchmark case with a much reduced computational time.