Computationally efficient high-fidelity plasma simulations by coupling multi-species kinetic and multi-fluid models on decomposed domains
Computationally efficient high-fidelity plasma simulations by coupling multi-species kinetic and multi-fluid models on decomposed domains
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DOI：
10.1016/j.jcp.2023.112073
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发表时间：
2023-03
期刊：
影响因子：
--
通讯作者：
I. Datta;U. Shumlak
中科院分区：
文献类型：
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作者：
I. Datta;U. Shumlak
发展了一种耦合多组分动力学等离子体模型和5 N矩多流体等离子体模型的数值方法。仿真域被分解，使得局部条件满足相应的等离子体模型的有效性区域。该方法允许通过将每个模型制定为一组守恒律并使用连续数值方法来求解分解域的子域中的每个模型的控制方程来进行混合模拟。模型通过子域界面的通量耦合。两种方法进行了探索，制定的通量，可以自我一致地表示两个等离子体模型。一种方法允许与5 N矩多流体等离子体模型一致的通量计算，并假设动力学等离子体模型的每个物种内的热力学平衡。第二种方法确保守恒的分布函数，以及质量，动量和能量，制定使用复合底层分布函数在子域接口的通量。该方法进行了比较，在1D 1V模拟的双稀疏波和等离子体鞘层使用WARPXM框架，它解决了每个模型使用不连续伽辽金有限元法。这两种方法制定的通量表现良好的子域界面分布函数接近麦克斯韦，与一致的方法更强大的偏差。磁化Kelvin-Helmholtz不稳定性在2D 2 V的模拟也使用一致的方法，这表明了潜在的域分解的混合方法，在促进加速和减少所需的计算资源高保真等离子体模拟，允许调查的问题，超出了目前的能力。
A numerical method is developed for coupling a multi-species kinetic plasma model with a 5N-moment multi-fluid plasma model. The simulation domain is decomposed such that the local conditions satisfy the corresponding plasma model's region of validity. The method allows for hybrid simulations by formulating each model as a set of conservation laws and using a continuum numerical method to solve each model's governing equations in the subdomains of the decomposed domain. The models are coupled through fluxes across subdomain interfaces. Two methods are explored for the formulation of the fluxes that can be self-consistently represented by both plasma models. One method allows for flux calculations consistent with the 5N-moment multi-fluid plasma model and assumes thermodynamic equilibrium within each species of the kinetic plasma model. The second method ensures conservation of the distribution function as well as mass, momentum, and energy by formulating the fluxes using a composite underlying distribution function at the subdomain interfaces. The methods are compared in 1D1V simulations of a double rarefaction wave and a plasma sheath using the WARPXM framework, which solves each model using the discontinuous Galerkin finite element method. Both methods for formulating the fluxes perform well as the subdomain interface distribution function approaches a Maxwellian, with the consistent method being more robust to larger deviations. A simulation of the magnetized Kelvin-Helmholtz instability in 2D2V is also performed using the consistent method, which demonstrates the potential of the domain-decomposed hybrid method in facilitating speedup and reduction in required computational resources for high-fidelity plasma simulations, allowing for the investigation of problems that are beyond current capabilities.