Drag Reduction through Pulsed Plasma Actuators

Drag reduction is a fundamental necessity in all aerodynamic designs, as it directly affects aircraft fuel efficiency which in turn affects endurance, range, and flight speed. Skin-friction drag reduction technology has a very significant impact in the future design of all aircraft, propellers, turbine blades, and wind-turbines, just to name few applications. Experimental and Direct Numerical Simulations results provide evidence that spanwise waves, of appropriate frequency and amplitude in the turbulent boundary layer, produce substantial skin-friction drag reduction. The generation and control of the spanwise waves however has been a significant practical barrier to the implementation of this technology, due to the requirement for complex moving parts that are too heavy and expensive to be added to an aircraft wing. In fact their additional weight and complex installation would essentially reduce or negate the benefits of the drag reduction. Lynntech proposes to use a proprietary technology based on Pulsed Plasma actuators, which are light-weight, simple to build, and easy to control, to generate turbulent boundary layer perturbations that induce significant skin-friction drag reduction. The proposed technology can be embedded in the wing, or propeller blade, to be flush with the wall and be electrically powered, thus avoiding additional ducting and other adverse characteristics that make competing skin-friction drag reduction approaches impractical for aeronautical applications. Lynntech's approach could also be exploited for dual use: the plasma actuators, in a different flight regime, could also be used to delay flow separation and thus delay stall onset, without the need to install an additional system. The proposed technology has a very wide outreach because it addresses a fundamental issue in aerodynamics and could be applied equally well to increase efficiency of aircraft within NASA programs, civilian transport aircraft, and military vehicles.