Effects of Flow Control on a Modified Glauert II Airfoil Section

Abstract

Several active flow control, as well as passive flow control, schemes were applied to a modified Glauert II "laminar" airfoil section. Zero mass-flux oscillatory suction and blowing and net mass-flux steady suction, or steady blowing were applied through a segmented spanwise slot. Static and dynamic pressures were measured. Pressures around the main element and within the wake were analyzed in order to gauge the performance through aerodynamic coefficients. Unsteady AFC was found to be effective as well as efficient. Several flow visualization techniques were used to aid the static analysis of the pressure distributions. Separation bubbles, recirculation zones, jump in stagnation location, spanwise-, and streamwise vortices were visualized. The present research attempts to quantify the control efficacy of unsteady zero mass-flux control and it's ability to reattach the flow and/or prevent separation. The concave curvature of the ramp was of concern as were the flow instabilities present due to the concavity.