Propulsion of a two-sphere swimmer

Klotsa, Daphne and Baldwin, Kyle A. and Hill, Richard J.A. and Bowley, R.M. and Swift, Michael R. (2015) Propulsion of a two-sphere swimmer. Physical Review Letters, 115 (24). 248102/1-248102/5. ISSN 1079-7114

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Abstract

We describe experiments and simulations demonstrating the propulsion of a neutrally-buoyant swimmer that consists of a pair of spheres attached by a spring, immersed in a vibrating fluid. The vibration of the fluid induces relative motion of the spheres which, for sufficiently large amplitudes, can lead to motion of the center of mass of the two spheres. We find that the swimming speed obtained from both experiment and simulation agree and collapse onto a single curve if plotted as a function of the streaming Reynolds number, suggesting that the propulsion is related to streaming flows. There appears to be a critical onset value of the streaming Reynolds number for swimming to occur. We observe a change in the streaming flows as the Reynolds number increases, from that generated by two independent oscillating spheres to a collective flow pattern around the swimmer as a whole. The mechanism for swimming is traced to a strengthening of a jet of fluid in the wake of the swimmer.

Item Type: Article
Additional Information: Propulsion of a Two-Sphere Swimmer. Daphne Klotsa, Kyle A. Baldwin, Richard J. A. Hill, R. M. Bowley, and Michael R. Swift. Phys. Rev. Lett. 115, 248102.
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Physics and Astronomy
Identification Number: 10.1103/PhysRevLett.115.248102
Depositing User: Hill, Richard
Date Deposited: 21 Apr 2017 13:01
Last Modified: 13 Oct 2017 01:06
URI: http://eprints.nottingham.ac.uk/id/eprint/42076

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