A Multi-physics Methodology for Four States of Matter
A Multi-physics Methodology for Four States of Matter
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DOI：
10.1007/s42967-019-00047-4
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发表时间：
2019-05
影响因子：
1.6
通讯作者：
L. Michael;S. Millmore;N. Nikiforakis
中科院分区：
文献类型：
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作者：
L. Michael;S. Millmore;N. Nikiforakis
我们提出了一个数值方法，同时数值模拟的四种状态的物质：气体，液体，弹塑性固体，等离子体。不同的，相互作用的物理过程的组合描述的可压缩的，惰性的，和反应形式的欧拉方程，多相方程，弹塑性方程，和电阻MHD方程。方程组的组合通常通过耦合用于实体建模的有限元和用于流体建模的CFD模型来求解，或者通过边界条件而不是完全材料离散化来包括材料效应。我们的同时解决方案的方法在于重铸的所有方程在相同的，双曲的形式，允许他们的解决方案在同一个网格上相同的有限体积的数值方案。我们结合使用尖锐和扩散界面方法来跟踪或捕获材料界面，具体取决于应用。不同方程组之间的通信（即，通过在系统的边界处的混合材料黎曼解算器（其代表物理材料边界）来促进由尖锐界面分离的材料）。为此，我们推导出近似的混合材料的黎曼解的特征方程的基础上，上述模型的每一对。为了证明新方法的适用性，我们考虑一个案例研究，在那里我们调查的可能性点燃的可燃气体，躺在液体中的金属容器，是由类似于雷击的等离子弧击中。我们研究了金属容器材料及其导电性对可燃气体点火的影响，以及额外的介电涂层的影响，气体的敏感性，以及密封和预损坏金属表面的情况之间的差异。
We propose a numerical methodology for the simultaneous numerical simulation of four states of matter: gas, liquid, elastoplastic solids, and plasma. The distinct, interacting physical processes are described by a combination of compressible, inert, and reactive forms of the Euler equations, multi-phase equations, elastoplastic equations, and resistive MHD equations. Combinations of systems of equations are usually solved by coupling finite element for solid modelling and CFD models for fluid modelling or including material effects through boundary conditions rather than full material discretisation. Our simultaneous solution methodology lies on the recasting of all the equations in the same, hyperbolic form allowing their solution on the same grid with the same finite volume numerical schemes. We use a combination of sharp- and diffuse-interface methods to track or capture material interfaces, depending on the application. The communication between the distinct systems of equations (i.e., materials separated by sharp interfaces) is facilitated by means of mixed-material Riemann solvers at the boundaries of the systems, which represent physical material boundaries. To this end, we derive approximate mixed-material Riemann solvers for each pair of the above models based on characteristic equations. To demonstrate the applicability of the new methodology, we consider a case study, where we investigate the possibility of ignition of a combustible gas that lies over a liquid in a metal container that is struck by a plasma arc akin to a lightning strike. We study the effect of the metal container material and its conductivity on the ignition of the combustible gas, as well as the effects of an additional dielectric coating, the sensitivity of the gas, and differences between scenarios with sealed and pre-damaged metal surfaces.