Effect of active oscillation of local surface on the performance of low Reynolds number airfoil

Abstract

In low Reynolds number conditions, laminar boundary layer separation and the consequent stall are usual, which are harmful to the aerodynamic characteristics of an airfoil. Energy addition to the flow by active oscillation of local surface can effectively restrain the flow separation and improve the performance. In the present paper, flow control based on active oscillation of local surface on an E387 airfoil is studied with numerical methods. The Reynolds number is Re = 30000 and the location of the oscillation region is a part of the upper surface near the leading edge. The respective relationships between the flow control effect and excitation parameters such as oscillation amplitude and excitation frequency are obtained. The flow mechanisms such as the behavior of the separation vortex and the variation of the equivalent shape are analyzed in both time-averaged and unsteady aspects. Furthermore, flow control effect at different angles of attack is also investigated. The results show that laminar separation can be effectively restrained, and the lift enhancement and drag reduction are evident.