A Numerical Tool for the Analysis of Bioinspired Aquatic Locomotion

Description

This book presents a novel method for the numerical simulation of swimming animals. It includes a review of the hydrodynamics of swimming, a description of the CFD model adopted, and a description of the results obtained by applying this model to the cownose ray. This method is developed for the open-source software OpenFOAM and relies on an overset mesh. A custom library is added to the solver to include the equations of the kinematics of the animal under investigation, combining the deformation of the fish fins with the computed displacement and rotation of the animal's body. The presented method helps investigate the dynamics of any animal moving in a fluid, provided that its kinematics is known, and in this work, it is applied to investigate the hydrodynamics of a cownose ray. This book is intended for researchers and engineers who aim to deeply understand the hydrodynamics of fish swimming and to design bioinspired autonomous underwater vehicles or novel propulsion systems. Preface Contents Acronyms 1 Introduction and State of the Art References 2 Hydrodynamics of Swimming 2.1 Classification of Swimming Modes 2.2 Hydrodynamic Principles of Fishes and Cetacean Locomotion 2.2.1 Swimming of a Waving Plate 2.2.2 Slender Body Theory 2.2.3 Vortices in the Wake 2.3 Efficiency of Fish Propulsion References 3 Model of Cownose Ray Locomotion 3.1 Rajiform Swimming 3.2 Bio-mechanical Model of Fin Kinematics 3.3 CFD Model of Cownose Ray Forward Swimming 3.3.1 Numerical Implementation References 4 Wake Structure and Swimming Performance of the Cownose Ray 4.1 Vortex Structures in the Wake and on the Leading Edge 4.1.1 Leading-Edge Vortex 4.2 Influence of Kinematic Parameters on Swimming Performances 4.2.1 Wavelength Effect 4.2.2 Frequency Effect 4.3 Angle of Attack 4.4 Strouhal Number References