Optimization of Propulsion Kinematics of a Flexible Foil Using Integrated CFD-CSD Simulations

Abstract

A computational simulation methodology, which combines a computational fluid dynamics technique and a computational structural dynamics technique, is employed to design a deformable foil of which kinematics is inspired by the propulsive motion of a fin or a tail of fish and cetacean. The unsteady incompressible Navier-Stokes equations are solved using a second-order accurate finite-difference method and an immersed-boundary method to effectively impose boundary conditions on complex moving boundaries. A finite-element-based structural dynamics solver is employed to compute the deformation of the foil due to interaction with fluid. A phase angle between pitching and heaving motions as well as the flexibility of the foil, which is represented by the Youngs modulus are varied to find out how these factors affect the propulsion efficiency.

Fluid-Structure Interaction Analysis of Hydrofoils in a Pulsating Flow

“…Although determining the hydrodynamic loads acting on an elastic hydrofoil is still quite challenging, a number of experimental and numerical studies have been devoted to this topic. Jiho You et al [1] and Suzanne [2] investigated the performance of elastic hydrofoil by CFD. Young [3,4] and Lin et al [5] used potential flow theory to predict the coupled flu id-structural response of elastic propellers under cavitating and non-cavitating conditions.…”