Patent ID: 8308112

Claim:
A vertical take-off and vertical landing rotor aircraft comprising: a surface over which a turbulent vortex generating airflow passes when in use, the turbulent flow being generated by a movement of the surface and a velocity of the airflow relative to the surface is greater than about 10 m/s, and a plasma actuator configured to generate a plasma above the surface of the vertical take-off and vertical landing rotor aircraft, the plasma coupling a directed momentum into the air surrounding the surface of the vertical take-off and vertical landing rotor aircraft to reduce separation of the airflow from the surface of the vertical take-off and vertical landing rotor aircraft, wherein the plasma actuator comprises: a dielectric, a first electrode on a first side of the dielectric, the first electrode having a first surface in contact with the dielectric and a second surface opposite the first surface exposed to the surrounding air, a second electrode covered by a second side of the dielectric, and an alternating current voltage source connected between the first and second electrodes, and wherein an amount of separation of the turbulent vortex generating airflow from the surface of the vertical take-off and vertical landing rotor aircraft depends on a velocity of the airflow and a frequency of the alternating current voltage source, wherein based upon the velocity of airflow, a frequency of the alternating current voltage source is selected so as to reduce the amount of separation of the airflow from the surface of the vertical take-off and vertical landing rotor aircraft.