An Aerodynamic Characterization for the Aeroacoustics of a Tilt-Rotor via a Vortex Particle Method

Tilt-rotor configurations have gained increasing interest in recent years, due to their versatility and potential applications in urban air mobility. These configurations offer unique advantages in maneuverability, compactness, and vertical take-off and landing capabilities, making them ideal candidates to address the challenges of modern urban transportation. However, their design presents significant challenges, requiring accurate modeling of complicated aerodynamic phenomena to enhance the performance, stability, and efficiency of multirotor systems, especially in urban environments where operational constraints are stringent. Vortex Particle Method (VPM) is one of the most suitable numerical methods for addressing these challenges, offering a mesh-free approach that minimizes numerical dissipation and accurately captures wake dynamics, which are critical for both performance optimization and tonal noise prediction. In this work, we assess the capabilities of FLOWUnsteady, an open-source state-of-the-art unsteady aerodynamic solver based on a reformulated VPM approach, and compare its results with Leonardo’s internal aerodynamic solver and experimental data. The validation is carried out through a series of increasingly complex test cases. We begin with an analytical benchmark to evaluate the theoretical properties of the reformulated VPM.We then validate our custom tonal noise prediction module, based on the FfowcsWilliams–Hawkings (FWH) analogy, using a well-known literature case. Finally, we present a comprehensive aerodynamic validation against experimental data, highlighting the strengths and current limitations of the method in both cruise and near-hover flight regimes.