An Investigation Of The Engineering Model For The Aerodynamic Interactions Of Propeller Slipstream With Aircraft Parts

Based on the mechanism of slipstream interaction, described in this thesis is firstly the interaction of the propeller slipstream with the wing,fuselage and horizontal tail. Subsequently, the changes in lift,drag and pitching moment are derived, giving an engineering model for the prediction of the increments in the aerodynamic characteristics caused by the interference between the propeller slipstream and the other parts of aircraft. This method offers a powerful means to the calculation of the aerodynamic interaction between the propeller and the aircraft, providing reliable data for the design of and aerodynamic calculation on propeller-powered aircraft.The ideal propeller model is used in this article to simplify the flow around the propeller. The potential flow theory is then applied to the overlap of the slipstream and the flow over the wing. The effects of the slipstream boundary are solved by the slipstream boundary condition met using the so-called vortex image method. Based on these considerations, the change in the circulation around the wing is obtained, and the velocities induced by the original vortices and the imaged vortices at the wing are subsequently derived. The present research also gives an analytical expression of the drag change due to the slipstream interference. Combined with the mechanism of slipstream influence on the fuselage and horizontal tail, the paper gives the change in the longitudinal aerodynamic characteristics caused by the slipstream.It is obvious that the results calculated using the method presented in this paper are compared better with the wind tunnel test data than those from the other existing engineering methods. Therefore, the code for the slipstream influence prediction provided in this investigation is effective.