Liquid drops and surface tension with smoothed particle applied mechanics
Liquid drops and surface tension with smoothed particle applied mechanics
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DOI：
10.1103/physreve.62.4968
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发表时间：
2000-10-01
影响因子：
2.4
通讯作者：
Posch, HA
中科院分区：
文献类型：
--
作者：
Nugent, S;Posch, HA
光滑粒子应用力学（SPAM），也称为光滑粒子流体力学，是一种用于模拟连续流的拉格朗日粒子方法。在这里，我们将其应用于形成的液滴，其蒸汽包围，在二维的货车范德华（vdW）流体。vdW状态方程的内聚压力引起粒子之间的吸引力，中心力，其相互作用范围被假定为超过SPAM运动方程中所有其他平滑力的相互作用范围。在此假设下，形成稳定的液滴，并且通过模拟很好地再现了vdW相图。在临界温度以下，平衡液滴的表面张力可以从其中心的压力过剩计算出来。它与由弱激发液滴的振动频率独立确定的表面张力非常一致。我们还研究了强烈变形的液滴进行大振幅振荡，这让人想起一个大的水球在微重力条件下的振荡。在附录中，我们评论的局限性SPAM研究违反角动量守恒，这是一个后果的非中心力贡献的完整的牛顿粘性应力张量。
Smoothed particle applied mechanics (SPAM), also referred to as smoothed particle hydrodynamics, is a Lagrangian particle method for the simulation of continuous flows. Here we apply it to the formation of a liquid drop, surrounded by its vapor, for a van der Waals (vdW) fluid in two dimensions. The cohesive pressure of the vdW equation of state gives rise to an attractive, central force between the particles with an interaction range which is assumed to exceed the interaction range of all the other smoothed forces in the SPAM equations of motion. With this assumption, stable drops are formed, and the vdW phase diagram is well reproduced by the simulations. Below the critical temperature, the surface tension for equilibrated drops may be computed from the pressure excess in their centers. It agrees very well with the surface tension independently determined from the vibrational frequency of weakly excited drops. We also study strongly deformed drops performing large-amplitude oscillations, which are reminiscent of the oscillations of a large ball of water under microgravity conditions. In an appendix we comment on the limitations of SPAM by studying the violation of angular momentum conservation, which is a consequence of noncentral forces contributed by the full Newtonian viscous stress tensor.