A generalized transport-velocity formulation for smoothed particle hydrodynamics
A generalized transport-velocity formulation for smoothed particle hydrodynamics
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DOI：
10.1016/j.jcp.2017.02.016
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发表时间：
2017-05
期刊：
影响因子：
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通讯作者：
Chi Zhang;Xiangyu Y. Hu;N. Adams
中科院分区：
文献类型：
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作者：
Chi Zhang;Xiangyu Y. Hu;N. Adams
标准光滑粒子流体力学(SPH)方法存在拉伸不稳定问题。在流体动力学模拟中，当负压出现时，这种不稳定性会导致颗粒聚集和空洞区。在固体动力学模拟中，它会导致非物理结构的碎裂。在这项工作中，阿达米等人的输运速度公式。(2013)[14]的推广是为了提供这一长期存在的问题的解决方案。除了施加全局背景压力外，还使用了可变背景压力来修正粒子的传输速度，完全消除了拉伸不稳定性。此外，通过定义缩短的平滑长度来局部化这样的修改。推广的公式适用于有自由表面和无自由表面的流体和固体材料。对流体和固体动力学问题的大量数值试验结果表明，新方法为多物理SPH模拟提供了一种统一的方法。
The standard smoothed particle hydrodynamics (SPH) method suffers from tensile instability. In fluid-dynamics simulations this instability leads to particle clumping and void regions when negative pressure occurs. In solid-dynamics simulations, it results in unphysical structure fragmentation. In this work the transport-velocity formulation of Adami et al. (2013) [14] is generalized for providing a solution of this long-standing problem. Other than imposing a global background pressure, a variable background pressure is used to modify the particle transport velocity and eliminate the tensile instability completely. Furthermore, such a modification is localized by defining a shortened smoothing length. The generalized formulation is suitable for fluid and solid materials with and without free surfaces. The results of extensive numerical tests on both fluid and solid dynamics problems indicate that the new method provides a unified approach for multi-physics SPH simulations.