Experiment study of propulsion-induced flow on aircraft aerodynamics

The characteristics of aircraft aerodynamic are the fundamental characteristics of aircraft. The influence of the propulsion-induced flow on the aerodynamic force is directly related to the accuracy of the aerodynamic modeling, the flight quality and the flight safety. A real turbojet engine is installed in a scaled-down aircraft model, and a more realistic static force measurement test is conducted under the different engine thrust force, air flow velocity and direction conditions. The results show that the influence of the propulsion-induced flow is mainly reflected in the axial force, the normal force and the pitching moment. The greater the engine thrust is, the more obvious the propulsion-induced effect is. And the maximum increment value of the normal force and the pitching moment appears with an angle of attack larger than the stall angle of attack. And the sideslip angle, wind speed (small range), as well as the control surfaces deflection caused by the aerodynamic increment is mainly manifested in the stall angle of attack. Therefore, the impact of propulsion-induced effect must be considered in the high angle of attack maneuver study.