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arXiv 0908.0416math.NAcs.NAmath-phmath.MPphysics.comp-phphysics.flu-dyn
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多尺度动力学方程的流体求解器无关混合方法

Fluid Solver Independent Hybrid Methods for Multiscale Kinetic equations

University of Ferrara(费拉拉大学)

Giacomo Dimarco, Lorenzo Pareschi

AI总结:

提出一种与流体求解器无关的混合方法,通过耦合蒙特卡罗动力学方法与宏观流体方法,高效求解多尺度动力学问题,并减少数值波动。

摘要:

在近期工作[G. Dimarco, L. Pareschi, Hybrid multiscale methods I. Hyperbolic Relaxation Problems, Comm. Math. Sci., 1, (2006), pp. 155-177], [G. Dimarco, L. Pareschi, Hybrid multiscale methods II. Kinetic equations, SIAM Multiscale Modeling and Simulation Vol 6., No 4,pp. 1169-1197, (2008)]中,我们开发了一个通用框架,用于构建能够有效处理某些双曲和动力学问题多尺度性质的混合算法。与先前方法不同,本文构造了一种适用于简化平衡系统任意有限体积或有限差分格式的方法。通过将求解动力学方程的蒙特卡罗技术与求解极限流体方程的宏观方法耦合,我们展示了如何比传统确定性/随机方法更快地求解多尺度流体动力学现象。此外,由于方案的混合性质,数值解相比标准蒙特卡罗方案具有更少的波动。给出了Boltzmann-BGK方程的应用,以展示新方法相对于经典动力学方程模拟方法的性能。

英文摘要:

In some recent works [G. Dimarco, L. Pareschi, Hybrid multiscale methods I. Hyperbolic Relaxation Problems, Comm. Math. Sci., 1, (2006), pp. 155-177], [G. Dimarco, L. Pareschi, Hybrid multiscale methods II. Kinetic equations, SIAM Multiscale Modeling and Simulation Vol 6., No 4,pp. 1169-1197, (2008)] we developed a general framework for the construction of hybrid algorithms which are able to face efficiently the multiscale nature of some hyperbolic and kinetic problems. Here, at variance with respect to the previous methods, we construct a method form-fitting to any type of finite volume or finite difference scheme for the reduced equilibrium system. Thanks to the coupling of Monte Carlo techniques for the solution of the kinetic equations with macroscopic methods for the limiting fluid equations, we show how it is possible to solve multiscale fluid dynamic phenomena faster with respect to traditional deterministic/stochastic methods for the full kinetic equations. In addition, due to the hybrid nature of the schemes, the numerical solution is affected by less fluctuations when compared to standard Monte Carlo schemes. Applications to the Boltzmann-BGK equation are presented to show the performance of the new methods in comparison with classical approaches used in the simulation of kinetic equations.

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。

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