An influence of pusher propeller cover on its performance : a concept of wind tunnel investigation

The paper describes a concept of wind tunnel investigation of the influence of the pusher propeller cover on its performance. The pusher propeller is one of the most popular types of the airplane propulsion, especially in light sport aircrafts and in the UAVs (Unmanned Aerial Vehicles). Its main advantages is that the engine with the pusher propeller does not affect the visibility from the cockpit and allows for placing an electronic equipment (for example, a camera) in the front part of the UAV’s fuselage. One of main disadvantages of pusher propeller is that it is partially covered by the fuselage and the wings of the airplane, thus the slipstream is distorted. This distortion may reduce the propeller thrust and efficiency. It may also cause vibrations of the propeller blades. This fact is well known, however it is difficult to find any quantitative information about reduction of the propeller performance. Taking it into account, it is worth to treat this subject and show a way to enhance the propeller performance. The wind tunnel tests, which concept has been described in the paper, will include measurements of total aerodynamic loads acting on the investigated object and on the propeller. Measurement of velocity distribution in the slipstream (by pressure measurement and by laser anemometry) will be included as well.