Uncertainty Quantification of Tiltrotor Whirl Flutter Aeroelastic Stability from Multibody Analysis

Tiltrotor aircraft maximum horizontal flight speed is limited by whirl flutter. Current research efforts focus on one side on experimentally investigating on the stability margins through specialized wind tunnel test-beds, and on the other side on developing efficient numerical tools, to both guide the development and gain information from experimental efforts. In this work, the development of TiPa, a software package providing a customizable interface to the general-purpose multibody dynamics solver MBDyn to provide a parametric tiltrotor model generation and investigation tool is presented. The tool is combined with DAKOTA, a state of the art Uncertainty Quantification (UQ) tool to form a complete aeroelastic stochastic analysis package. Two strategies for the parametric model generation are presented. One is based on the definition of complete MBDyn tiltrotor models while the other one relies on the generation of two different subsystems to be assembled through a substructuring approach. Some promising early results and assessment are presented, together with the expected future research direction.