arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1910.03080math.APcs.NAmath.NA
收藏

齐次Landau方程的粒子方法

A particle method for the homogeneous Landau equation

Jose A. Carrillo, Jingwei Hu, Li Wang, Jeremy Wu

摘要:

我们提出了一种新的确定性粒子方法来数值近似朗道方程的等离子体。基于一个新的变分公式的梯度流的朗道方程,我们正则化的碰撞算子,使粒子的解决方案的意义。这些粒子的解决方案解决了一个大型的耦合常微分方程系统,保留了所有的重要属性的朗道运营商,即守恒的质量,动量和能量,以及熵的衰减。我们说明了我们的新方法,显示其性能在几个测试用例,包括物理相关的情况下的库仑相互作用。与精确解和谱方法相比,保持了二阶精度。此外,一个有效的实现方法,通过树码进行了探索。这给出了一个概念的证明,我们的方法的实际使用时,再加上经典的PIC方法的弗拉索夫方程。

英文摘要:

We propose a novel deterministic particle method to numerically approximate the Landau equation for plasmas. Based on a new variational formulation in terms of gradient flows of the Landau equation, we regularize the collision operator to make sense of the particle solutions. These particle solutions solve a large coupled ODE system that retains all the important properties of the Landau operator, namely the conservation of mass, momentum and energy, and the decay of entropy. We illustrate our new method by showing its performance in several test cases including the physically relevant case of the Coulomb interaction. The comparison to the exact solution and the spectral method is strikingly good maintaining 2nd order accuracy. Moreover, an efficient implementation of the method via the treecode is explored. This gives a proof of concept for the practical use of our method when coupled with the classical PIC method for the Vlasov equation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑