论文标题
移动网格上的时间依赖性辐射流体动力学
Time Dependent Radiation Hydrodynamics on a Moving Mesh
论文作者
论文摘要
我们描述了漫画的辐射流体动力求解器的结构和实现，漫画是大规模平行代码的移动网格流体动力学模块，Charm n-body Gravity solver（changa）。我们使用江等算法（2014）算法后使用降低光速近似速度来求解时间依赖的辐射转移方程。通过将辐射传递方程式写为广义保护方程，我们将这些方程的传输部分求解在非结构化的Voronoi网格上。然后，我们使用隐式求解器解决了江等（2014）之后辐射传递方程的源部分，然后将其与流体动力方程式息息。使用隐式求解器的使用确保可靠的收敛性并保留这些方程的保护性能，即使在源项在辐射和物质之间的小耦合时间尺度引起的情况下也很僵硬。我们介绍了有限数量的测试用例（能源保护，动量保护，动态扩散，线性波，交叉束和多个阴影）的结果，以表现出具有分析结果和数值稳定性的收敛性。我们还表明，在光学上有多个来源的情况下，它在定性上产生正确的结果。
We describe the structure and implementation of a radiation hydrodynamic solver for MANGA, the moving-mesh hydrodynamics module of the large-scale parallel code, Charm N-body GrAvity solver (ChaNGa). We solve the equations of time dependent radiative transfer using a reduced speed of light approximation following the algorithm of Jiang et al (2014). By writing the radiative transfer equations as a generalized conservation equation, we solve the transport part of these equations on an unstructured Voronoi mesh. We then solve the source part of the radiative transfer equations following Jiang et al (2014) using an implicit solver, and couple this to the hydrodynamic equations. The use of an implicit solver ensure reliable convergence and preserves the conservation properties of these equations even in situations where the source terms are stiff due to the small coupling timescales between radiation and matter. We present the results of a limited number of test cases (energy conservation, momentum conservation, dynamic diffusion, linear waves, crossing beams, and multiple shadows) to show convergence with analytic results and numerical stability. We also show that it produces qualitatively the correct results in the presence of multiple sources in the optically thin case.
