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arXiv 1709.07804cond-mat.soft
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频率相关的两个固体球之间的流体动力相互作用

Frequency-dependent Hydrodynamic Interaction Between Two Solid Spheres

Gerhard Jung, Friederike Schmid

摘要:

流体动力学相互作用在软物质科学的许多领域中起着重要的作用。在隐式溶剂模拟中,各种技术,如布朗或斯托克斯动力学明确包括后验流体动力学相互作用,通过使用来自斯托克斯方程的流体动力学扩散张量。然而,这个方程假设相互作用是瞬时的,这是一个理想化的近似,只在长时间尺度上有效。在本文中,我们进一步分析的可压缩流体中的水动力相互作用的时间依赖性的基础上的线性纳维-斯托克斯方程。理论结果表明,流体的可压缩性对频率相关的对相互作用有显著的影响。的流体动力学理论的预测相比,分子动力学模拟的两个固体球在Lennard-Jones流体。对于这个系统,我们重建记忆功能,通过扩展逆Volterra技术。仿真数据与理论结果吻合较好,因此,该理论可用于实现非马尔可夫模型中的动态一致性水动力相互作用。

英文摘要:

Hydrodynamic interactions play an important role in many areas of soft matter science. In simulations with implicit solvent, various techniques such as Brownian or Stokesian dynamics explicitly include hydrodynamic interactions a posteriori by using hydrodynamic diffusion tensors derived from the Stokes equation. However, this equation assumes the interaction to be instantaneous which is an idealized approximation and only valid on long time scales. In the present paper, we go one step further and analyze the time-dependence of hydrodynamic interactions in a compressible fluid on the basis of the linearized Navier-Stokes equation. The theoretical results show that the compressibility of the fluid has a significant impact on frequency-dependent pair interactions. The predictions of the hydrodynamic theory are compared to molecular dynamics simulations of two solid spheres in a Lennard-Jones fluid. For this system we reconstruct memory functions by extending the inverse Volterra technique. The simulation data agree very well with the theory, therefore, the theory can be used to implement dynamically consistent hydrodynamic interactions in the increasingly popular field of non-Markovian modeling.

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。

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