Application of FSI (Fluid Structure Interaction) to biomimetic robot fish

Abstract

The flexible material is often used for a caudal fin in a robot fish. In that case, the rigid body modeling of the caudal fin is not appropriate for simulating the turbulent flow field around the robot fish. In the present study, FSI (Fluid Structure Interaction) method is applied to the simulation of fish swimming considering the flexibility of caudal fin. Computational fluid dynamics (CFD) is carried out with computational structural mechanics for investigating the swimming characteristics of biomimetic robot fish. For CFD simulation, unsteady Reynolds-averaged Navier-Stokes (URANS) formulation is applied to the complex turbulent flow fields generated by the movement of the robot fish. For finite element analysis (FEA) simulation, the governing equations for structural mechanics are solved. In the present study, the flexibility of the caudal fin is focused and its contribution to the turbulent wakes is investigated.