Stabilizing effect of flexibility in the wake of a flapping foil

Abstract

The wake of a flexible foil undergoing pitching oscillations in a low-speed hydrodynamic tunnel is used to examine the effect of chord-wise foil flexibility in the dynamical features of flapping-based propulsion. We compare the regime transitions in the wake with respect to the case of a rigid foil and show that foil flexibility inhibits the symmetry breaking of the reverse Bénard-von Kármán wake reported in the literature. A momentum balance calculation shows the average thrust to be up to three times greater for the flexible foil than for the rigid foil. We explain both of these observations by analyzing the vortex dynamics in the very near wake.

10 pages

References in corpus (2)

• Resonance and propulsion performance of a heaving flexible wing
• How wing compliance drives the efficiency of self-propelled flapping flyers

Cited by in corpus (4)

• Classification of vortex patterns of oscillating foils in side-by-side configurations
• How shape and flapping rate affect the distribution of fluid forces on flexible hydrofoils
• Wake and aeroelasticity of a flexible pitching foil
• Vortex transition and thermal mixing by pitching a perforated flexible panel