Aerodynamic control of a semi-span wing with a divergent trailing edge using synthetic jets.

摘要

An experimental investigation was performed to evaluate the aerodynamic control effectiveness of trailing edge synthetic jets on a finite swept-wing model with a divergent trailing edge. In the wind tunnel experiments, the trailing 30% of a NACA 652 -- 215 wing section was modified to incorporate a divergent trailing edge with a trailing edge thickness of 3% chord. The divergent trailing edge produced a small separated region downstream of the trailing edge which could be leveraged, at low angles of attack, by the synthetic jets. Two configurations of trailing edge synthetic jet actuators were tested: the first issued in the streamwise direction at the base of the trailing edge, and the second issued perpendicular to the lower surface of the model at 99% chord. The model contained an array of seven pockets along the span to house the interchangable actuator designs. Qualitative changes in the flow were observed using smoke wire flow visualization at a chord Reynolds number of Rec = 17,000. The lift and drag forces were measured by a two-axis force balance at a chord Reynolds number of Rec = 85,000, and ensemble averaged PIV measurements were taken to quantify the changes in the flow field near the synthetic jet orifice. The combined effect of a divergent trailing edge and synthetic jets produced a significant increase in lift accompanied by a modest increase in drag through all angles of attack up to stall. The lift increment was attributed to increased circulation around the model which resulted in greater suction side velocities, lower pressure side velocities, and a downward deflection in the wake. Furthermore, proportional aerodynamic control was achieved by varying the synthetic jet output and spanwise location.