Preliminary Flight Tests of a Hinge-Less Roll Control Effecter

Introduction T HERE has been a growing research effort to achieve effective hinge-less flight control, spurred on by advances in fluidic control. For purposes of stealth, reduced vehicle weight, increased robustness and damage tolerance as well as compactness, hinge-less methodology is extremely attractive. Hinge-less control can be implemented through either continuous or oscillatory flow manipulation. Continuous manipulation can be achieved using blowing. Past research efforts have shown jet flaps1,2 and circulation control3,4 to be effective at augmenting lift and varying pitching moment. A recent study has shown that a highly deflected (normal to the surface) jet flap can match the performance of a Gurney flap using moderate jet momentum coefficients.5 However, continuous blowing invariably requires drawing air off the engine’s compressor or using shaft power to drive a compressor. Ducting is also required to route the air through its ejection path. Consequently, weight and thrust penalties can be incurred. It would be advantageous to the designer to have the flexibility to employ a modular air-injection system that can be placed locally where control is required. The system can be configured to function as a jet flap or used for augmenting existing control effecters (forming a blown flap). Such a system would have the advantage of not requiring pneumatic lines and can be employed in flight vehicles where a pneumatic source is not present (e.g., unmanned aerial vehicles). In this Note we detail the design and implementation of a self-contained modular blower system. Blower design details are elucidated, as are verification of the blower’s effectiveness as a roll control device through flight testing.