渐近保持PIC算法在等离子体粒子模拟中的应用

Application of asymptotic preserving PIC method in the plasma particle simulation

针对准中性Vlasov-Poisson系统中多尺度物理参数共存的问题开展研究,采用渐近保持格式推导出与Vlasov方程相耦合的Poisson方程。数值模拟了一维等离子体在真空中的膨胀,比较了渐近保持PIC算法与传统PIC算法模拟结果的异同。结果表明:两种算法在满足多尺度中小尺度量限制的前提下,其结果保持高度一致;且在克服小尺度量束缚时,渐近保持PIC算法依然可以正确地模拟等离子体的物理行为,大大节省了计算时间。

The existing problem of multi-scale parameters in the quasi-neutral Vlasov-Poisson system was studied,using asymptotic preserving scheme to induce a Poisson equation coupled with Vlasov equation. One dimensional plasma expansion in vacuum was simulated,the asymptotic preserving PIC and classical PIC results were compared. The simulated results show that two methods have a good agreement while satisfying the smaller scale constraint,and the asymptotic preserving scheme still simulates correctly the physics behavior of plasma while free of the smaller scale constraint,the calculated time is saved intensely.