Effect of airfoil camber on small autogyro rotors

A gyroplane rotor is pneumatically driven and extracts power from an airstream. That power extraction is seen as a reduction in the speed of the air behind the rotor disk. This video demonstrates the effects that airfoil camber have on that airspeed reduction. It also shows how the camber affects the lifting efficiency of a rotor ( lift to drag ratio ). The lift to drag ratio is determined by the angle the rotor takes relative to the oncoming air ( angle of attack ). As a rotor produces force roughly perpendicular it's plane of rotation, at very low angles, most of the force it will produce will act vertically. The larger the angle, more of the force is redirected backwards, making the rotor harder to push through the air. For the purpose of a gyroplane, the rotor should be as level as possible, as it reduces the force needed to counteract rotor resistance to keep the machine flying.