Numerical Study on Combustion-Driven Jet Actuation for Aerodynamic Control of Airfoil Flows

Abstract

In this study, a numerical investigation is conducted on combustion-driven pulsed-jet actuation to control the flow around a lifting surface. Based on relevant experimental measurements and computations, high-speed jets are generated from the impulsive variation in pressure at the actuator boundary. A supersonic jet flow is momentarily generated by combustion in a reaction chamber of the actuator, and the flow interacts with the external flow around the lifting surface and alters the aerodynamic characteristics. The computational results indicate that the flow control performance of the jet actuation is significant at a high-incidence angle of attack, such as beyond the stall angle, whereas the impact is minimal at low angles of attack, such as in the linear lift region. Repetitive jet actuation can produce additional momentum to the external flow and alters the pressure distribution on the suction surface, particularly downstream of the actuator location. This pressure variation from the actuation yields an additional lift force on the lifting surface and reduces the amplitude of the aerodynamic moment at a given angle of attack, thus enhancing the aerodynamic performance of the airfoil.

Keywords

• combustion-powered actuation
• active flow control
• impulse jet actuation
• flow separation
• computational fluid dynamics