Flight Mechanics Analysis Of A Type Dish-shaped Rotor Aircraft

The dish-shaped rotor aircraft is a new type of configuration rotor aircraft which combines the advantages of vertical take off and landing capabilities with the high forward speed.It consists of a coaxial rotor,ring wing,thrust ducted fan,landing gear and a control system.In this paper,flight mechanics characteristics of a type of dish-shaped rotor aircraft were analyzed.Firstly,the flight dynamics model of the aircraft was established.This dissertation built the main rotor nonlinear aerodynamic mathematical model based on the Blade-Element theory.The aerodynamic model of dish-shaped wing was obtained by CFD calculation and test data,combined with the previous research results.The aerodynamic model of ducted fan thrust,landing gear and control system were built using empirical formula.Finally,the aerodynamic model of each component was integrated to establish the flight dynamics model of the aircraft.Secondly,the special flight mode of the aircraft was analyzed.The flight state of the aircraft was divided into helicopter mode,transitional flight mode and stable rotation flight mode.In this paper,the influence factors and aerodynamic advantages of the rotor stable rotation were analyzed.The steady state of the rotor to the flight process was introduced.The maneuvering strategy of the aircraft in different flight modes was obtained.Thirdly,the flight performance of the aircraft in different flight modes was calculated.Finally,according to the theoretical model,the program for calculating the force and moment of each pneumatic component was established,and the simulation model was built in MATLAB/simulink environment.The trim of the aircraft was calculated.The handling and stability characteristics were analyzed.