Fish-Inspired Oscillating and/or Undulating Hydrofoil in a Free Stream Flow: A Review on Thrust Generation Mechanisms

A review of recent literature on thrust generation mechanisms by a hydrofoil, bioinspired from fish locomotion is presented. The present work considers fish-inspired periodic kinematics of three types: pitching, heaving, and undulations along with the combination of some of these motions. The pitching corresponds to the tail of the fish while heaving and undulation correspond to that of the body. The undulation also corresponds to the surface of the body; for certain fishes. Both numerical and experimental studies in this arena have been reviewed. The present review follows the classification of oscillatory and undulatory motion. We discuss oscillatory motion with emphasis on pitching, heaving, and the combination of these two motions. In undulatory motion, we cover body undulation and surface undulation motion as a propulsive mechanism. We compare and contrast wake signatures, thrust, and propulsive efficiencies for different motion types. A future outlook, which may help researchers to identify open questions, has been provided.