Lift Augmentation Using Pulsed Combustion for Externally Blown Flaps

This study investigates the use of sub-cubic-inch resonant pulse combustors as active flow control (AFC) devices to augment lift in high-lift flight regimes through the implementation of externally blown flaps. Recent advancements in AFC have demonstrated the effectiveness of periodic momentum injection in mitigating flow separation, particularly in high-deflection control surface scenarios. Pulse combustors, with their ability to produce high-frequency, high-momentum pulsed jets are well-suited to meet the reduced-frequency demands of such applications. In this research, miniature Helmholtz-type pulse combustors are integrated near the wing flaps to produce pulsed jet actuation over the flap surface. Large flap deflections commonly induce boundary layer separation, reducing lift. Injecting momentum across the deflected surface can delay or mitigate separation under selected operating conditions, resulting in measurable lift augmentation. This approach has the potential to improve short takeoff and landing (STOL) capabilities in current and future aircraft designs. The paper will detail the combustor design and integration, experimental setup, and preliminary wind tunnel findings that demonstrate the feasibility and benefits of using pulse combustors in blown flap configurations.