Numerical Study of Vortex Dynamics of Flexible Wing Propulsors

摘要

An airfoil or a wing-section oscillating in a fluid flow models the locomotion of certain aquatic and avian animals that propel themselves by flapping their fins and wings. The wing or the wing-section is usually flexible. It is well known that modeling the deformation in the flexible structure as a traveling wave, certain kinds of wave motion lead to high values of thrust and propulsive efficiency in a fluid. These results point to how some animals achieve high efficiencies during locomotion. However, these investigations do not account for the dynamics of the flexible structure interacting with the unsteady fluid dynamics. Here, a numerical simulation coupling the fluid and structure dynamics shows that high propulsive efficiencies are a consequence of fluid-elastic interaction and not some prescribed motions of the solid structure in a moving fluid.