Analysis Of Aerodynamic Interference Characteristics Of Pre-Flight State Of Composite Aircraft

Coaxial helicopter in forward flight counter propeller to maintain lift, at the same time to provide the required thrust forward. On the lower rotor spacing is bound to increase, rotor rotation plane will forward lead to side spacing and side spacing is small, relatively small spacing on one side of the prone to caused because of the waving serious collision problem, and also increase the power loss of the power system。This paper proposes the installation of two ducted tail propulsion with the front wing and short composite gas balance body dynamic layout. Put forward the two caudal ducted thrust to provide pre flight, in order to maintain the overall balance of the body installed in the front of the fuselage short wings, and provide supplementary lift, as a result of the main rotor only need to produce lift, to avoid the risk of collision of reducing engine power consumption.Firstly the whole gas of the UAV aerodynamic layout is described, drawing the main structure of the 3D SolidWorks model, the specific parameters are calculated. Then the theoretical analysis of ducted tail propulsion and short front wing, the dynamic characteristics of the theoretical basis for the later analysis of thrust ducted gas, principle analysis of wing generating lift. Analysis on the thrust characteristics of ducted fan based on CFD simulation based on the theory of ducted tail propulsion, analysis the impact of different variables and different propeller environment on aerodynamic characteristics.Based on CFD simulation method analysis of wing on the rear propulsion gas ducted in forward flight of aerodynamic interference characteristics, of airfoil flow characteristics analysis of wing tip part in forward flight will produce vortex. By changing the installation position of the culvert, wingtip vortex into the ducted fan position will be different. In view of this phenomenon were analyzed in different culvert installation position when the aerodynamic characteristics of ducted propulsion, and is not affected by the influence of the short wing aerodynamic characteristics do comparative analysis. The results indicate that the double tail ducted propulsion with front short wing aerodynamic layout will not only provide for the UAV flight thrust, and the aerodynamic characteristics of ducted fan is not affected by the wingtip vortex, to prove the rationality of the layout.