Effects of Perturbation on the Flow Over Nonslender Delta Wings

Abstract

An experimental investigation is presented to reveal the flow physics and turbulence statistics of nonslender delta and diamond wings with a sweep angle of Λ = 40° under perturbation condition with the amplitude of Δα = +Δαsinωet = ±0.5° during Te=2π/ωe= 0.5s. The experiments are carried out using the techniques of dye visualization and Stereoscopic Particle Image Velocimetry (stereo-PIV) on the plan view and cross flow plane for the cases of stationary and perturbed wing as the angle of attack is varied within 7°≤α≤17°. In order to perform a comparison based on the wing planform, diamond wing is designed from the composition of same shape of the delta wing and an attachment part mounted on its trailing edge. This study also provides information about effects of trailing edge attachment mounted on a generic nonslender delta wing under current test conditions. It can be concluded that perturbation is beneficial in the control of flow over both wings at relatively high angles of attack, α.The duration required for occurrence of flow control increases for the current period and time of perturbation, when the trailing edge attachment (diamond wing case) is employed. Beyond this, trailing edge attachment takes role in attenuation of turbulence statistics, where leading edge vortex breaks down. © 2015, American Institute of Aeronautics and Astronautics, Inc.