A Space-Time Accurate Finite-State Inflow Model for Aeroelastic Applications

Dynamic wake inflow modelling is one of the main issues in the development of efficient and high-fidelity simulation tools for design of new generation rotorcraft. The aim of this paper is the development of a LTI, space-accurate, finite-state model for the prediction of dynamic wake inflow perturbations of helicopter rotors in arbitrary steady flight, extracted from high-fidelity aerodynamics solvers. The proposed dynamic wake inflow model, coupled with sectional aerodynamic load theories, may be conveniently applied for aeroelastic and aero-servo-elastic analysis of rotors with the introduction of a limited number of additional states, thus turning out to be suitable for real-time predictions. The outcomes of numerical investigations concerning a helicopter rotor in hovering and forward flight conditions are shown to demonstrate the capability of the introduced model to capture with a good level of accuracy the time evolution of the wake inflow radial distribution on blades of rotors subject to arbitrary perturbations.