Active Flow Control on the Stingray UAV: Transient Behavior

A new class of Unmanned Aerial Vehicle (UAV) is investigated, based on the flying ducted fan concept. The vehicle uses a mechanically simplified control approach employing synthetic jet active flow control in lieu moving control surfaces or articulated rotor blades. As a result, the UAV's propulsion and control systems are simplified to a single moving part, a fixed pitch propeller. This mechanical simplicity makes the application of active flow control particularly attractive for development of mini and micro UAVs. The active control of flow separation over a lifting surface as a means of discrete state aerodynamic control briefly approached from the theoretical standpoint, then explored from an experimental standpoint. Effectiveness of a synthetic jet active flow control technique for generating the intended aerodynamic force changes on a ducted stator vane is explored and validated by experiments on a 3-D duct model. Positive results of these experiments lead to development of a full-scale (2-3 Kg. G.W.) proof of concept dynamic model on which the application of flow control was successfully demonstrated.