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arXiv · 2211.13369

Propulsive performance of oscillating plates with time-periodic flexibility

David Yudin·Daniel Floryan·Tyler Van Buren
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Abstract

We use small-amplitude inviscid theory to study the swimming performance of a flexible flapping plate with time-varying flexibility. The stiffness of the plate oscillates at twice the frequency of the kinematics in order to maintain a symmetric motion. Plates with constant and time-periodic stiffness are compared over a range of mean plate stiffness, oscillating stiffness amplitude, and oscillating stiffness phase for isolated heaving, isolated pitching, and combined leading edge kinematics. We find that there is a profound impact of oscillating stiffness on the thrust, with a lesser impact on propulsive efficiency. Thrust improvements of up to 35% relative to a constant-stiffness plate are observed. For large enough frequencies and amplitudes of the stiffness oscillation, instabilities emerge. The unstable regions may confer enhanced propulsive performance; this hypothesis must be verified via experiments or nonlinear simulations.

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David Yudin, Daniel Floryan, Tyler Van Buren. 2022-11-24. Propulsive performance of oscillating plates with time-periodic flexibility. https://doi.org/10.1017/jfm.2023.166

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