Experimental Investigation of Dynamic Pitching Effects on a Delta Wing with Blown Jet

Active flow control (AFC) devices can be utilized for stall mitigation, enhancing aerodynamic performance, and performing efficient maneuvers by altering the localized flow around different regions of a vehicle. A blown jet was installed along the upper surface of a flat plate delta wing half-span model with a 60° sweep angle in the University of Dayton Water Tunnel (UDWT). This study investigates the use of a blown jet to mitigate the breakdown of the leading-edge vortex. The mass flow rate and the corresponding momentum coefficient were controlled using a closed loop PI controller to alter the lift at various α using the actuator. Forces and moments were recorded to measure the performance. Static and dynamic tests were conducted to measure the change in behavior of vortex breakdown during quasi-steady and unsteady pitching at different moment coefficient. Measurable differences in lift coefficient are observed at a higher angle of attack with AFC. However, the impact of AFC diminishes with an increase in reduced frequency. Preliminary flow visualization revealed a bifurcation of the blown jet exit angle caused by the local pressure gradients at a range of angles of attack depending on the moment coefficient.