Flow control of a NACA 0015 airfoil using a chordwise array of synthetic jets

The purpose of this research is to maximize the flow control effectiveness of a synthetic jet array mounted along the chord of an NACA 0015 airfoil. This is attempted using two approaches: 1) reduce synthetic jet losses due to three-dimensional effects and 2) increase synthetic jet exit velocity. For a given actuator dimension, synthetic jet exit velocity is increased 288% by sizing the Helmholtz frequency of the jet cavity to match the resonant frequency of the actuators. For the exit velocities tested, the array of synthetic jets was found to be ineffective in delaying flow separation without the addition of chordwise fences placed on both sides of the jet array. With the fences, at an angle-of-attack of 15.5 degrees, lower pressures are observed on the upper surface of the airfoil, increasing lift and suggesting a reduction of spanwise flow. Key parameters adversely affecting jet performance include actuator variation, actuator age and fatigue, and cavity leakage.