Comprehensive Aerodynamic And Acoustic Insights Into The Volocopter-2X During Flight

Abstract

The aerodynamic behavior and aeroacoustic signature of the Volocopter 2-X aircraft are studied by performing high-fidelity CFD simulations during climb and descent. To gain more detailed insight into the flight states, three half-model simulation setups were investigated: an isolated rotor configuration, a setup without the fuselage and a full aircraft model. Additionally, the noise emissions of these configurations were simulated using a Ffowcs Williams-Hawkings based computational aeroacoustic (CAA) code and were compared to flight test measurements. Realistic flight conditions for the simulations were achieved by performing a flight-mechanical trim of the half model and adapting the rotor speeds to achieve a periodic state for the acoustic simulations. The VC-2X demonstrates both rotor-rotor and rotor-structure interactions that affect the aerodynamic performance and acoustic emissions. While interactions with the fuselage and supporting beams induce additional thrust fluctuations, rotor-rotor interactions remain the dominant source of unsteady aerodynamic effects. Blade-vortex interactions (BVI) were identified in both examined flight conditions, with increased intensity during descent. In contrast, the climb condition revealed stronger rotor wake-structure interactions. A comparison between the half-model simulations and flight test data shows good agreement in terms of overall sound pressure levels and spectral content. This indicates that the half-model approach is capable of predicting noise under realistic flight conditions. However, the prediction of specific tonal components and directivity patterns showed discrepancies due to additional effects such as crosswinds and rotor speed variability in flight test.