arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1903.04799physics.flu-dyncond-mat.softphysics.comp-ph
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压缩分子的格子Boltzmann模型

A Lattice Boltzmann Model for Squirmers

Michael Kuron, Philipp Stärk, Christian Burkard, Joost de Graaf, Christian Holm

摘要:

蠕动体是一种简单而有指导意义的微型游泳者模型,它采用球形游泳者表面的有效滑动速度来描述其自推进。我们用格子Boltzmann(LB)方法解决流体动力学问题,该方法非常适合于涉及复杂边界条件的时间依赖性问题。将蠕动体转化为LB是相对直接的,但是需要出乎意料的精细网格分辨率来准确地捕获物理流场和行为。我们证明了这一点,使用四个基本的流体动力学测试:两个远场流-准确的流体动力学力矩和蠕动蠕动的相互作用-和两个需要近场准确地解决-一个蠕动局限于一个管和一个散射的球形障碍物-LB是能够做到的网格分辨率。我们发现很好的协议(数值)使用其他流体动力学求解器在相同的几何形状得到的结果,并确定一个最低要求的分辨率,以实现这一再现。我们讨论了我们的算法的背景下,其他流体动力学求解器,并提出了其应用前景多蠕动问题。

英文摘要:

The squirmer is a simple yet instructive model for microswimmers, which employs an effective slip velocity on the surface of a spherical swimmer to describe its self-propulsion. We solve the hydrodynamic flow problem with the lattice Boltzmann (LB) method, which is well-suited for time-dependent problems involving complex boundary conditions. Incorporating the squirmer into LB is relatively straight-forward, but requires an unexpectedly fine grid resolution to capture the physical flow fields and behaviors accurately. We demonstrate this using four basic hydrodynamic tests: Two for the far-field flow---accuracy of the hydrodynamic moments and squirmer-squirmer interactions---and two that require the near field to be accurately resolved---a squirmer confined to a tube and one scattering off a spherical obstacle---which LB is capable of doing down to the grid resolution. We find good agreement with (numerical) results obtained using other hydrodynamic solvers in the same geometries and identify a minimum required resolution to achieve this reproduction. We discuss our algorithm in the context of other hydrodynamic solvers and present an outlook on its application to multi-squirmer problems.

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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