Enhanced hybrid vortex particle method for aerodynamic analysis of tiltrotor rotor/wing interactions

Aiming to elucidate the complex aerodynamic interactions between rotor and wing during hovering, forward flight, and transition modes of tiltrotor aircraft, an enhanced hybrid vortex particle method is developed. This method leverages Neumann boundary conditions and Hess equivalence principle for efficient computational analysis. By incorporating a single panel-multi vortex particles conversion and adaptive vortex particle quantity control, the adaptive adjustment of vortex particle quantity is achieved, further optimizing the computational efficiency. Validation against wind tunnel data demonstrates precision and efficiency of the method compared to traditional viscoelastic vortex particle methods. Subsequent numerical simulations and flow field analysis of the rotor/wing model unveil intricate aerodynamic interactions. In hovering mode, while the wing's blocked downwash slightly enhances rotor lift, the dominant negative lift due to significant wing download adversely impacts overall load-carrying capacity. Increasing collective pitch mitigates this lift loss. During transition, the rotor wake initially induces substantial lift loss on the wing, followed by a notable increase and negligible influence in later phases. The wings alter structure of the rotor wake, but the effect on rotor performance is minimal. In forward flight, rotor/wing aerodynamic interactions is weak, albeit with a reduced lift-to-drag ratio. These findings provide valuable insights into the aerodynamic complexities of tiltrotor aircraft, contributing to the development of aeroelastic stability analysis, high-fidelity flight dynamics model development and performance optimization.