Vortex Ring State Prediction Using a Mid-fidelity Comprehensive Approach

Vortex Ring State (VRS), a hazardous condition during rotorcraft descent, appears more problematic for high disc loadings aircraft like tiltrotors and eVTOL multi-rotors. Traditionally, semi-empirical models were calibrated using flight data to predict VRS. Recent advancements in modeling techniques and computational resources made it possible to predict the VRS by solving Navier-Stokes equations via Eulerian (VTM) or Lagrangian (VPM) approaches and conventional Computational Fluid Dynamics (CFD). The study aims to validate the capability of the open-source VPM code DUST to predict VRS boundaries and rotor loads and support the development of appropriate simulation models for the assessment of aircraft handling qualities. Finally, the effect of the rotor dynamics will be introduced to better simulate and design an escaping VRS strategy to enhance the correct training to increase future rotorcraft safety.