Embedding Lagrangian Sink Particles in Eulerian Grids
Embedding Lagrangian Sink Particles in Eulerian Grids
复制标题
在欧拉网格中嵌入拉格朗日汇粒子
DOI：
10.1086/421935
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
R. Klein
中科院分区：
文献类型：
--
作者：
M. Krumholz;C. McKee;R. Klein
我们介绍了一种新的计算方法，将拉格朗日粒子嵌入到欧拉计算中。重力塌陷或吸积的模拟通常会产生密度大大超过模拟中平均密度的区域。这些密集区域需要极小的时间步长来保持数值稳定性。光滑粒子流体力学(SPH)程序通过引入非吸积的汇粒子来解决这个问题，而欧拉代码可能会引入固定的汇单元。然而，到目前为止，还没有一种方法允许欧拉码跟踪多个移动物体的吸积。我们已经通过将汇粒子能力扩展到欧拉流体动力学代码来消除这一限制。我们对这种新方法进行了测试，发现它与解析解非常吻合。在分析我们的汇粒子方法时，我们提出了一种根据流体力学程序的数值粘性来计算圆盘粘性参数α的方法，并用它计算了笛卡尔自适应网格加密程序的α。我们还给出了这一新方法的一个简单应用：研究当激波撞击正在经历Bondi吸积的粒子时，从Bondi到Bondi-Hoyle吸积的转变。
We introduce a new computational method for embedding Lagrangian sink particles into a Eulerian calculation. Simulations of gravitational collapse or accretion generally produce regions whose density greatly exceeds the mean density in the simulation. These dense regions require extremely small time steps to maintain numerical stability. Smoothed particle hydrodynamics (SPH) codes approach this problem by introducing nongaseous, accreting sink particles, and Eulerian codes may introduce fixed sink cells. However, until now there has been no approach that allows Eulerian codes to follow accretion onto multiple, moving objects. We have removed that limitation by extending the sink particle capability to Eulerian hydrodynamics codes. We have tested this new method and found that it produces excellent agreement with analytic solutions. In analyzing our sink particle method, we present a method for evaluating the disk viscosity parameter α due to the numerical viscosity of a hydrodynamics code and use it to compute α for our Cartesian adaptive mesh refinement (AMR) code. We also present a simple application of this new method: studying the transition from Bondi to Bondi-Hoyle accretion that occurs when a shock hits a particle undergoing Bondi accretion.
影响因子：
3.2
作者：
V. Mannings;A. Boss;S. Russell
通讯作者：
V. Mannings;A. Boss;S. Russell