Reduced entropic model for studies of multidimensional nonlocal transport in high-energy-density plasmas
Reduced entropic model for studies of multidimensional nonlocal transport in high-energy-density plasmas
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DOI：
10.1063/1.4926824
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发表时间：
2015-08-01
影响因子：
2.2
通讯作者：
Tikhonchuk, V.
中科院分区：
文献类型：
--
作者：
Del Sorbo, D.;Feugeas, J. -L.;Tikhonchuk, V.
高能量密度等离子体的流体动力学模拟需要对能量通量的详细描述。对于低和中原子序数材料，主要机制是电子传输，这可能是需要动力学建模的非局域现象。在本文中，我们提出并测试了基于简化福克-普朗克方程的第一角矩的非局部模型的结果。由于熵关系（玻尔兹曼 H 定理），这个多维模型是封闭的。它提供了对电子分布函数的更好描述，从而能够在流体动力学框架内研究小尺度动力学效应。给出了由热通量驱动的电子等离子体和离子声波不稳定性的例子，并与经典公式进行了比较。 (C) 2015 AIP 出版有限责任公司。
Hydrodynamic simulations of high-energy-density plasmas require a detailed description of energy fluxes. For low and intermediate atomic number materials, the leading mechanism is the electron transport, which may be a nonlocal phenomenon requiring a kinetic modeling. In this paper, we present and test the results of a nonlocal model based on the first angular moments of a simplified Fokker-Planck equation. This multidimensional model is closed thanks to an entropic relation (the Boltzman H-theorem). It provides a better description of the electron distribution function, thus enabling studies of small scale kinetic effects within the hydrodynamic framework. Examples of instabilities of electron plasma and ion-acoustic waves, driven by the heat flux, are presented and compared with the classical formula. (C) 2015 AIP Publishing LLC.