arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2005.01785astro-ph.EPastro-ph.IMastro-ph.SR
收藏

一个适用于星周盘中行星形成模拟的二矩辐射流体力学方案

A two-moment radiation hydrodynamics scheme applicable to simulations of planet formation in circumstellar disks

Julio David Melon Fuksman, Hubert Klahr, Mario Flock, Andrea Mignone

摘要:

我们提出了一个辐射流体动力学的数值代码设计为一个模块的免费提供PLUTO代码。我们采用灰色近似,并包括辐射转移以下的两个时刻的方法,通过施加M1封闭的辐射场。这种封闭允许在扩散和自由流动限制的辐射传输的描述,并能够描述高度各向异性的辐射传输,可以预期在附近的吸积行星在原行星盘。为了减少由于辐射场和物质场的时间尺度不一致而引起的计算量,我们采用算子分裂的方法分别对它们的演化方程进行积分,并采用分段的方法对辐射方程进行演化。我们进一步提高了代码的效率,通过采用降低光速近似(RSLA)。辐射场演化方程的积分方案依赖于隐式-显式方案,其中辐射-物质相互作用项被隐式积分,而通量通过Godunov型求解器被积分。该模块适用于在笛卡尔坐标、球坐标和柱坐标中的1维、2维和3维的一般天体物理计算,并且可以在旋转框架上实现。我们证明了算法的性能在不同的数值基准,特别注意的适用性的RSLA计算物理过程中的原行星盘。我们展示了2D模拟的垂直对流盘和3D模拟的气体吸积行星的核心,这是第一个解决了两个时刻的方法。

英文摘要:

We present a numerical code for radiation hydrodynamics designed as a module for the freely available PLUTO code. We adopt a gray approximation and include radiative transfer following a two-moment approach by imposing the M1 closure to the radiation fields. This closure allows for a description of radiative transport in both the diffusion and free-streaming limits, and is able to describe highly anisotropic radiation transport as can be expected in the vicinity of an accreting planet in a protoplanetary disk. To reduce the computational cost caused by the timescale disparity between radiation and matter fields, we integrate their evolution equations separately in an operator-split way, using substepping to evolve the radiation equations. We further increase the code's efficiency by adopting the reduced speed of light approximation (RSLA). Our integration scheme for the evolution equations of radiation fields relies on implicit-explicit schemes, in which radiation-matter interaction terms are integrated implicitly while fluxes are integrated via Godunov-type solvers. The module is suitable for general astrophysical computations in 1, 2, and 3 dimensions in Cartesian, spherical and cylindrical coordinates, and can be implemented on rotating frames. We demonstrate the algorithm performance on different numerical benchmarks, paying particular attention to the applicability of the RSLA for computations of physical processes in protoplanetary disks. We show 2D simulations of vertical convection in disks and 3D simulations of gas accretion by planetary cores, which are the first of their kind to be solved with a two-moment approach.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑