Combustion-Powered Actuation for Dynamic-Stall Suppression: High-Mach Simulations and Low-Mach Experiments

Abstract

An investigation on the dynamic-stall-suppression capabilities of combustion-powered actuation applied to a tabbed VR-12 airfoil is presented. In the first section, the results from the computational fluid dynamics simulations carried out at Mach numbers of 0.3 and 0.4 are presented. Several geometric parameters are varied, including the slot chordwise location and angle. Actuation-pulse amplitude, frequency, and timing are also varied. The two-dimensional simulations suggest that cycle-averaged lift increases of approximately 4 and 8% with respect to the baseline airfoil are possible at Mach numbers of 0.4 and 0.3 for deep and near-deep dynamic-stall conditions. In the second section, the static-stall results from low-speed wind-tunnel experiments are presented. The low-speed experiments and high-speed computational fluid dynamics suggest that slots oriented tangential to the airfoil surface produce stronger benefits than slots oriented normal to the chord line. The low-speed experiments confirm that chordwise slot locations suitable for Mach 0.3–0.4 stall suppression (based on computational fluid dynamics) will also be effective at lower Mach numbers.