Plasma Actuators for Hingeless Aerodynamic Control of an Unmanned Air Vehicle

Abstract

The use of dielectric barrier discharge plasma actuators for hingeless flow control over a 47-deg 1303 unmanned combat air vehicle wing is described. Control was implemented at the wing leading edge to provide longitudinal control without the use of hinged control surfaces. Wind-tunnel tests were conducted at a chord Reynolds number of 4.12 x 105 and angles of attack ranging from 15 to 35 deg to evaluate the performance of leading-edge plasma actuators for hingeless flow control. Operated in an unsteady mode, the actuators were used to alter the flowfield over the lee-side wing to modify the aerodynamic lift and drag forces on the vehicle. Multiple configurations of the plasma actuator were tested on the lee side and wind side of the wing leading edge to affect the wing aerodynamics. Data acquisition included force-balance measurements, laser fluorescence, and surface flow visualizations. Flow visualization tests mainly focused on understanding the vortex phenomena over the baseline uncontrolled wing to aid in identifying optimal locations for plasma actuators for effective flow manipulation. Force-balance results show considerable changes in the lift and drag characteristics of the wing for the plasma-controlled cases compared with the baseline cases. When compared with the conventional traditional trailing-edge devices, the plasma actuators demonstrate a significant improvement in the control authority in the 15- to 35-deg angle-of-attack range, thereby extending the operational flight envelope of the wing. The study demonstrates the technical feasibility of a plasma wing concept for hingeless flight control of air vehicles, in particular, vehicles with highly swept wings and at high angles of attack flight conditions in which conventional flaps and ailerons are ineffective.