Разработка трехмерной гибридной модели бесстолкновительного расширения плазменного облака в разреженную ионизованную замагниченную окружающую среду

Abstract

The paper presents the results of developing a hybrid three-dimensional model of collisionless interaction in plasma flows. This model considers ions in kinetical terms (simulated as a set of individual particles) and describes electrons in terms of continuum mechanics (simulated as a fluid). We present the system of equations behind the mathematical model and the physical conditions limiting its applicability. The system includes equations describing ion motion in electromagnetic fields, the quasineutrality equation, equations for calculating the total current density, non-radiative Maxwell's equations, and the generalised Ohm's law. We outline a numerical method for solving our hybrid model equations and describe an algorithm for solving the system of equations over time. We focus on the numerical method for solving the induction equation, which takes possible discontinuous solutions into account and preserves the divergence-free condition for the magnetic field. The paper discusses the issues of increasing the spatial approximation accuracy for the numerical scheme used to solve the induction equation. We present numerical simulation results for collisionless expansion of a plasma cloud into a rarefied ionised gas in the presence of an external magnetic field. These results were obtained using our computer code that implements the hybrid model described. The paper demonstrates some numerical properties of the digital simulation developed, specifically, how the order of accuracy for the numerical scheme approximation designed to solve the induction equation affects numerical simulation results