Efficiency of Fish Propulsion
Abstract
It is shown that the system efficiency of a self-propelled flexible body is ill-defined unless one considers the concept of quasi-propulsive efficiency, defined as the ratio of the power needed to tow a body in rigid-straight condition over the power it needs for self-propulsion, both measured for the same speed. Through examples we show that the quasi-propulsive efficiency is the only rational non-dimensional metric of the propulsive fitness of fish and fish-like mechanisms. Using two-dimensional viscous simulations and the concept of quasi-propulsive efficiency, we discuss the efficiency two-dimensional undulating foils. We show that low efficiencies, due to adverse body-propulsor hydrodynamic interactions, cannot be accounted for by the increase in friction drag.
Keywords
Cite
@article{arxiv.1409.7263,
title = {Efficiency of Fish Propulsion},
author = {A. P. Maertens and M. S. Triantafyllou and D. K. P. Yue},
journal= {arXiv preprint arXiv:1409.7263},
year = {2015}
}