Multibody Dynamics Simulation and Experimental Investigation of a Model-Scale Tiltrotor

Abstract

Abstract : The objective of this investigation is to develop a multibody analytical simulation model to predict the dynamic response, aeroelastic stability, and blade loading of a soft-inplane tiltrotor wind-tunnel model and correlate that with experimental data. A Joint Vertical Aircraft Task Force is currently developing requirements to meet Army and Navy needs for a heavy lift transport rotorcraft that is expected to include, at a minimum, a 20-ton payload lift capability. Development of soft-inplane tiltrotor technology is beneficial for providing viable lightweight hub design options for this future application. Experimental testing, either in flight testing or with a wind tunnel test article, is becoming prohibitively expensive. Advanced simulation and modeling of these complex tiltrotor hub configurations using multibody dynamics codes may prove to be an alternative to such expensive experimental verifications in the future. The use of multibody dynamics codes to predict and reduce the risk of encountering aeromechanical instabilities and adverse loading situations for a soft-inplane tiltrotor hub design is detailed in this investigation. Comprehensive rotorcraft-based multibody analyses enable simulation and modeling of the rotor system to a high level of detail such that complex mechanics and nonlinear e ects associated with control system geometry and joint free-play may be considered. The influence of these and other nonlinear e ects on the aeromechanical behavior of the tiltrotor model is examined. A parametric study of the design parameters which influence the aeromechanics of the soft-inplane rotor system is also included in this investigation.