A blended continuous-discontinuous finite element method for solving the multi-fluid plasma model
详细信息 查看全文
- 作者：E.M. Sousa ; sousae@uw.edu" class="auth_mail" title="E-mail the corresponding author ; U. Shumlak shumlak@uw.edu" class="auth_mail" title="E-mail the corresponding author
- 关键词：High-order ; Discontinuous Galerkin finite element method ; Continuous Galerkin finite element method ; Implicit&ndash ; explicit (IMEX) scheme ; Multi-fluid plasma model
- 刊名：Journal of Computational Physics
- 出版年：2016
- 出版时间：1 December 2016
- 年：2016
- 卷：326
- 期：Complete
- 页码：56-75
- 全文大小：1858 K
文摘
The multi-fluid plasma model represents electrons, multiple ion species, and multiple neutral species as separate fluids that interact through short-range collisions and long-range electromagnetic fields. The model spans a large range of temporal and spatial scales, which renders the model stiff and presents numerical challenges. To address the large range of timescales, a blended continuous and discontinuous Galerkin method is proposed, where the massive ion and neutral species are modeled using an explicit discontinuous Galerkin method while the electrons and electromagnetic fields are modeled using an implicit continuous Galerkin method. This approach is able to capture large-gradient ion and neutral physics like shock formation, while resolving high-frequency electron dynamics in a computationally efficient manner. The details of the Blended Finite Element Method (BFEM) are presented. The numerical method is benchmarked for accuracy and tested using two-fluid one-dimensional soliton problem and electromagnetic shock problem. The results are compared to conventional finite volume and finite element methods, and demonstrate that the BFEM is particularly effective in resolving physics in stiff problems involving realistic physical parameters, including realistic electron mass and speed of light. The benefit is illustrated by computing a three-fluid plasma application that demonstrates species separation in multi-component plasmas.