CG Envelope Design For The Preliminary Program Of The Tiltrotor Aircraft

Tiltrotor aircraft is a new rotorcraft，which combines the advantages of helicopter V/STOL andfixed wing aircraft high-speed cruising and has huge application potential.Tiltrotor aircraft center ofgravity envelope design quality not only affects the aircraft flight performance，a more direct impacton the economy and security of the aircraft used.Currently rarely seen a comprehensive study on thecombining the tiltrotor aircraft center of gravity envelope with the general parameters.Based on the research results at home and abroad，for tiltrotor aircraft center of gravity envelopeand general parameter selection， the paper conducted the following studies:Firstly， establish a detailed tiltrotor aircraft flight dynamics of nonlinear mathematical model offull variable.Find a nonlinear mathematical model trim method，preliminarily analyze the trimfeatures and the sport modal characteristics in fixed-wing mode and helicopter mode.Secondly，according to the tiltrotor aircraft center of gravity affect its maneuverability andstability，after calculating the longitudinal center of gravity limits under different loads，and todetermine the calculation method tiltrotor aircraft center of gravity envelope.In XV-15tiltrotor aircraftas an example，to calculate a range of two-dimensional and three-dimensional aircraft’ center ofgravity envelope and the results were analyzed to verify the feasibility of the method.Finally，typical aircraft loading program and the tiltrotor aircraft general parameter sensitivityanalysis and design optimization were studied,laid the foundation for future tiltrotor aircraft overalldesign and optimization.