The influence of airfoil kinematics on the formation of leading-edge vortices in bio-inspired flight

Abstract

The formation process of leading-edge vortices has been investigated experimentally using Particle Image Velocimetry. Various airfoil kinematics have been tested, including asymmetric and peak-shifted plunging motions, and are evaluated for Re∈=∈30,000 and a reduced frequency range of 0.2∈≤∈k∈≤∈0.33. By measuring the growth in the leading-edge vortex during the dynamic-stall process, the vortex pinch-off process is examined based on the concept of an optimal vortex formation time. The various kinematics are then evaluated with respect to their associated vortex strength, timing and convection into the wake. © 2010 Springer-Verlag Berlin Heidelberg.