Integeral Design And Aerodynamic Characteristics Research Of The Multiple-Ducted Fan UAV

A Multiple-Ducted Fan UAV with decoupling control was brought up because of the curruent Ducted Fan UAV couldn’t fly fast and its flight control couping is serious. This UAV was composed of a main duct system, two adjusting duct systems and a ducted tail rotor, the power and control of Each duct system was independent, the control of the UAV’s attitude depended on the cooperation of the duct systems in order to realise the UAV flight control decoupling, the ducted tail rotor with asymmetric layout of the UAV not only could produce axial force to make the UAV could fly fast, but also could bring about radial force to provide the additional lift force for aircraft to achieve the purpose of reducing power consumption and improving the efficiency of the UAV. The Multiple-Ducted Fan UAV not only had the advantages of vertical taking off and landing, good flexibility, high propulsion efficiency, low noise, good concealment,etc. which belong to the current Ducted Fan UAV,but also had the advantages of fixed wing aircraft which can fly fast.It also effectively solved the problems of the curruent Ducted Fan UAV whose flight control couping is serious.First of all, this article determined the UAV’s materials and overall layout, presented its dynamics model and attitude control mode and analyzed its typical flight conditions. The general parameters of the UAV were selected and analyzed. Each part of the UAV was preliminarily designed and the3D CATIA model of the UAV was established. Secondly, the aerodynamic characteristics of ducted fan, the main lift device of the UAV, was analyzed. The analysis focused on the ducted fan with coaxial rotors and the hover characteristics, axial flow characteristics and forward flight characteristics were got respectively. Thirdly, the flow field characteristics of the UAV’s body were analyzed and the lift and drag characteristics under different flight velocities and attack angles were got by the method of CFD. Finally, the aerodynamic performance of the ducted tail rotor with asymmetric structure was studied by method of theoretical analysis and numerical simulation. Results show that this ducted tail rotor with asymmetric layout not only could produce axial force to control the spacecraft attitude, but also could bring about radial force to provide the additional lift force for aircraft.In summary, A Multiple-Ducted Fan UAV with decoupling control was designed generally and its key parts’aerodynamic characteristics was analyzed.All of those have laied a firm foundation for follow-up study.The research also will provide technical support for the further design of ducted fan UAV, especially for the one who contains ducted fan with coaxial rotor or Multiple-Ducted Fan.