A study of self-propelled elastic cylindrical micro-swimmers using modeling and computation

JOURNAL OF COMPUTATIONAL PHYSICS

卷:314

Article

Shi, Lingling¹  Canic, Suncica¹  Quaini, Annalisa¹  Pan, Tsorng-Whay¹ 

[1] Univ Houston, Dept Math, 4800 Calhoun Rd, Houston, TX 77204 USA

关键词: Micro-swimmers;    Immersed boundary method;    Fluid-structure interaction;    Reduced 1D model;   

DOI  :  10.1016/j.jcp.2016.02.071

来源: Elsevier

【 摘 要 】

We study propulsion of micro-swimmers in 3D creeping flow. The swimmers are assumed to be made of elastic cylindrical hollow tubes. The swimming is generated by the contractions of the tube's elastic membrane walls producing a traveling wave in the form of a step-function traversing the swimmer from right to left, propelling the swimmer from left to right. The problem is motivated by medical applications such as drug delivery. The influence of several non-dimensional design parameters on the velocity of the swimmer is investigated, including the swimmer aspect ratio, and the amplitude of the traveling wave relative to the swimmer radius. An immersed boundary method based on a finite element method approach is successfully combined with an elastic spring network model to simulate the two-way fluid-structure interaction coupling between the elastic cylindrical tube and the flow of a 3D viscous, incompressible fluid. To gain a deeper insight into the influence of various parameters on the swimmer speed, a reduced 1D fluid-structure interaction model was derived and validated. It was found that fast swimmers are those with large tube aspect ratios, and with the amplitude of the traveling wave which is roughly 50% of the reference swimmer radius. It was shown that the speed of our optimal swimmer is around 1.5 swimmer lengths per second, which is at the top of the class of all currently manufactured micro-swimmers swimming in low Reynolds number flows (Re = 10(-6)), reported in [11]. (C) 2016 Elsevier Inc. All rights reserved.

【 授权许可】

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