Numerical Investigation of Rotor-Gust Acoustic Interactions Using the OVERFLOW CFD Solver

<p>The rapid expansion of Urban Air Mobility (UAM) necessitates high-fidelity modeling to predict and mitigate the noise signatures of electric vertical take-off and landing (eVTOL) aircraft within dense urban landscapes. A critical unknown in community-noise certification is the aeroacoustic response of rotors to unsteady inflow conditions. This research addresses this gap by investigating the aerodynamic and acoustic behavior of a representative rotor subjected to time-harmonic inflow disturbances. By establishing a robust numerical framework, this thesis quantifies the relationship between periodic atmospheric gusts and their impact on rotor performance, unsteady blade loading, and subsequent sound radiation. The research consists of a rigorous three-stage methodology. It begins with the implementation and verification of a momentum-source harmonic gust generator integrated directly into the OVERFLOW CFD solver. To ensure the reliability of the rotor physics, the Joby 2017 rotor is then validated across hover, axial, and edgewise flight conditions using experimental benchmarks from the Virginia Tech Stability Wind Tunnel. The framework concludes by coupling the verified gust generator with the validated rotor environment, allowing for the isolation of aerodynamic and acoustic deltas specifically attributable to the periodic inflow disturbances. Verification confirms the successful implementation of the harmonic gust generator, while validation against Virginia Tech experimental data demonstrates strong agreement across hover, axial, and edgewise flight regimes in terms of both performance metrics and the acoustic results at the blade-passing frequency (BPF). This establishes a high-fidelity baseline for the subsequent gust-rotor interaction studies. Results from those interaction studies indicate that while mean thrust and torque remain nearly constant despite varying gust intensities, unsteady load fluctuations increase significantly, producing distinct spectral sidebands at the blade-passing frequency (BPF). Acoustic analysis reveals modest amplification of tonal components at the BPF alongside a slight attenuation of low-frequency radiation. This framework serves as a versatile precursor for investigating the non-stationary aerodynamic and acoustic phenomena encountered by vehicles operating in increasingly congested and turbulent urban airspace.</p>

Name thesis:degree_name

Master of Science in Aerospace Engineering

Level thesis:degree_level

Thesis - Open Access

Discipline thesis:degree_discipline

Aerospace Engineering

Year

2026

Author dc:creator

• Mills, Jordan

• Joby; High-Fidelity; OVERFLOW; eVTOL; UAM; AAM; Acoustics
• Aerodynamics and Fluid Mechanics
• Aeronautical Vehicles
• Other Aerospace Engineering
• Propulsion and Power

Repository record dc:identifier

https://commons.erau.edu/edt/967

OAI identifier oai:identifier

oai:commons.erau.edu:edt-2018