BCP Particle Positioning Techniques for DSMC Method

Zhi-bo Wang ； Lin-ying Li ； Bin Zhang ； Hong Liu

《Journal of Aeronautics, Astronautics and Aviation》 51卷3期 Vol.51 No.3 (2019/09) Pp. 225-236

https://doi.org/10.6125/JoAAA.201909_51(3).01

摘要

This study introduces a background Cartesian grid positioning (BCP) method into the DSMC method, which can quickly build the relationship between particle position and structured grid, thereby improving the computational efficiency of particle tracing with a structured grid. By constructing the geometric relationship of background Cartesian and structured grids, the BCP method can be applied to several simulations with complex configurations that retain the advantage of Cartesian grids, that is, rapid particle tracing. On the basis of a comprehensive analysis of computational efficiency and computer memory consumption, a method is proposed to determine the relative density of background Cartesian grids. The accuracy and efficiency of the BCP method are verified by simulating a classical 2-D hypersonic cylinder flow. Results show that the BCP method can significantly decrease the computational cost of particle tracing. This decreasing trend becomes increasingly obvious when a high Mach or large time steps and small size grids is selected.

關鍵字

DSMC ； Cartesian grid ； Structured grid ； Particle position ； Flow around a cylinder