论文标题
均衡的有限体积方案,用于几乎稳定的绝热流
Well-balanced finite volume schemes for nearly steady adiabatic flows
论文作者
论文摘要
我们提出了均衡的有限体积方案,旨在用重力近似欧拉方程。它们基于一种新型的局部稳态重建。这些方案保留了稳定绝热流的离散等效物,其中包括非静态平衡。所提出的方法在笛卡尔,圆柱和球形坐标中起作用。该方案不与任何特定的数值通量绑定,并且可以与Euler方程的任何一致的数值通量结合在一起,该方程提供了极大的灵活性并简化了整合到任何标准有限的体积算法中。此外,这些方案可以应付一般的状态凸方程,这在天体物理应用中尤为重要。呈现一阶和二阶精确版本的方案及其扩展到几个空间维度。与标准方案相比,在各种数值实验中证明了均衡方案的出色性能。所选的数值实验包括笛卡尔和球形几何形状中的简单一维问题,以及具有复杂的状态多物理方程的圆柱几何形状中恒星积聚的二维模拟。
We present well-balanced finite volume schemes designed to approximate the Euler equations with gravitation. They are based on a novel local steady state reconstruction. The schemes preserve a discrete equivalent of steady adiabatic flow, which includes non-hydrostatic equilibria. The proposed method works in Cartesian, cylindrical and spherical coordinates. The scheme is not tied to any specific numerical flux and can be combined with any consistent numerical flux for the Euler equations, which provides great flexibility and simplifies the integration into any standard finite volume algorithm. Furthermore, the schemes can cope with general convex equations of state, which is particularly important in astrophysical applications. Both first- and second-order accurate versions of the schemes and their extension to several space dimensions are presented. The superior performance of the well-balanced schemes compared to standard schemes is demonstrated in a variety of numerical experiments. The chosen numerical experiments include simple one-dimensional problems in both Cartesian and spherical geometry, as well as two-dimensional simulations of stellar accretion in cylindrical geometry with a complex multi-physics equation of state.