Stability Analysis Of Coupled Rotor/fuselage/landing Gears/shipboard System For Coaxial Twin-rotor Helicopter

With the development of ocean industry in the world and the increasing use of ship-based helicopters,the safety of take-off and landing of ship-based helicopters under the conditions of ship motion and complex sea conditions is particularly important.However,when the "ship resonance" occurs,it is easy to cause aircraft damage,so the research on the coupled stability of helicopter surface becomes more and more important.This paper mainly establishes the dynamic model of single-rotor helicopter and coaxial twin-rotor helicopter coupled with ship surface,and explores and studies the problem of "ship resonance".The coupled rotor/fuselage/landing gears/shipboard system for the dynamic simulation of a shipboard helicopter was developed using multi-body dynamics approach on the Basis of Forefathers.The body model considers three degrees of freedom of translation,roll,pitch and yaw in longitudinal,transverse and vertical directions.The rotor model uses rigid blades and considers the swing and swing degrees of freedom of the rotor.The model based on Hamilton principle can be easily realized by computer programming and can easily add parameters of each component to the model.Secondly,the dynamic equations of rotor/fuselage/landing gear/ship surface coupled motion are established,State-space eigenvalue method and fourth-order Runge-Kutta method are used to analyze the response in time domain and dynamic stability of shipboard helicopter rotor/body coupling system under ship excitation of different amplitude and frequency.The dynamic response of a coaxial twinrotor helicopter rotor/fuselage/landing gear/ship surface coupling system without considering aerodynamic effects is analyzed.The dynamic response of the coaxial twin-rotor helicopter rotor/fuselage/landing gear/ship surface coupling system is also analyzed after considering the aerodynamic effect on the dynamic response of the system.The analysis of this paper provides theoretical guidance for the dynamic design of the rotor/fuselage/landing gear/ship surface coupling system of coaxial twin-rotor helicopter.