Hydrodynamic simulations with the Godunov SPH
Hydrodynamic simulations with the Godunov SPH
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DOI：
10.1111/j.1365-2966.2011.19021.x
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发表时间：
2011-05
期刊：
影响因子：
--
通讯作者：
G. Murante;S. Borgani;R. Brunino;S. Cha
中科院分区：
文献类型：
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作者：
G. Murante;S. Borgani;R. Brunino;S. Cha
我们目前的结果的基础上实施的Goddom光滑粒子流体动力学（GSPH），最初由犬冢（2002），在GADGET-3流体动力学代码。我们首先回顾了GSPH离散的时刻和能量守恒方程的推导，从卷积这些方程的插值内核。这些方程的数值实现的两个最重要的方面是（a）从每对粒子之间的黎曼问题的解获得的流体速度和压力的出现，以及（B）没有人工粘性项。我们进行了三个不同的控制流体动力学三维测试，即Sod激波管，开尔文-亥姆霍兹不稳定性的发展在剪切流测试，和“斑点”测试描述的冷云移动对热风的演变。我们的试验结果在许多方面证实并扩展了Cha（2010）最近获得的结果：（i）相对于SPH，GSPH提供了对接触不连续性的更好描述，从而避免了虚假压力的出现;（ii）GSPH能够跟踪气体动力学不稳定性的发展，例如Kevin-Helmholtz和Rayleigh-Taylor不稳定性;（iii）因此，GSPH描述了剪切流试验中卷曲结构的发展和“团块”试验中冷云的溶解。我们还详细讨论了GSPH的性能改变其实施的不同方面的影响。我们的测试结果表明，GSPH实际上是一个非常有前途的流体动力学计划，也耦合到一个N体求解器，天体物理和宇宙学的应用。[删节]
We present results based on an implementation of the Godunov Smoothed Particle Hydrodynamics (GSPH), originally developed by Inutsuka (2002), in the GADGET-3 hydrodynamic code. We first review the derivation of the GSPH discretization of the equations of moment and energy conservation, starting from the convolution of these equations with the interpolating kernel. The two most important aspects of the numerical implementation of these equations are (a) the appearance of fluid velocity and pressure obtained from the solution of the Riemann problem between each pair of particles, and (b the absence of an artificial viscosity term. We carry out three different controlled hydrodynamical three-dimensional tests, namely the Sod shock tube, the development of Kelvin-Helmholtz instabilities in a shear flow test, and the "blob" test describing the evolution of a cold cloud moving against a hot wind. The results of our tests confirm and extend in a number of aspects those recently obtained by Cha (2010): (i) GSPH provides a much improved description of contact discontinuities, with respect to SPH, thus avoiding the appearance of spurious pressure forces; (ii) GSPH is able to follow the development of gas-dynamical instabilities, such as the Kevin--Helmholtz and the Rayleigh-Taylor ones; (iii) as a result, GSPH describes the development of curl structures in the shear-flow test and the dissolution of the cold cloud in the "blob" test. We also discuss in detail the effect on the performances of GSPH of changing different aspects of its implementation. The results of our tests demonstrate that GSPH is in fact a highly promising hydrodynamic scheme, also to be coupled to an N-body solver, for astrophysical and cosmological applications. [abridged]