Date of Award

Spring 5-4-2026

Access Type

Thesis - Open Access

Degree Name

Master of Science in Aerospace Engineering

Department

Aerospace Engineering

Committee Chair

Anastasios S. Lyrintzis

Committee Chair Email

lyrintzi@erau.edu

First Committee Member

Vladimir V. Golubev

First Committee Member Email

golubd1b@erau.edu

Second Committee Member

R.R. Mankbadi

Second Committee Member Email

reda.mankbadi@erau.edu

College Dean

James W. Gregory

Abstract

This thesis presents the development and validation of a methodology for predicting total acoustic emissions from a one-fifth scale electric vertical takeoff and landing (eVTOL) rotor in both hover and edgewise flight conditions. The approach couples sectional two-dimensional Reynolds-Averaged Navier-Stokes (2D-RANS) airfoil simulations with rotor loading predictions from the Comprehensive Hierarchical Aeromechanics Rotorcraft Model (CHARM), tonal noise calculations using the acoustic solver PSU-WOPWOP, and broadband noise predictions from the UCD-QuietFly framework. Boundary-layer inputs traditionally obtained from the viscous-inviscid solver, XFOIL, were replaced with higher-fidelity 2D-RANS results from OpenFOAM to better capture low-Reynolds-number flow physics, including laminar-turbulent transition and laminar separation bubble behavior.

Predicted acoustic spectra were validated against experimental measurements obtained in the Virginia Tech Stability Wind Tunnel. Results demonstrate that turbulence model selection influences local boundary-layer development and sectional aerodynamic loading, leading to modest variations in tonal blade-passing-frequency levels at 4000 revolutions per minute (RPM) and broadband spectral differences of approximately 4 dB. Despite these spectral variations, integrated overall sound pressure level predictions show limited sensitivity to turbulence model choice. At 2000 RPM, broadband noise mechanisms dominate the total sound pressure level, with transitional turbulence models predicting thinner boundary layers and reduced high-frequency trailing-edge noise relative to fully turbulent assumptions.

To improve the prediction of spectral regions that are under-resolved by the mid-fidelity aerodynamic framework, higher-fidelity three-dimensional Delayed Detached Eddy Simulation (3DDDES) tonal noise results obtained using OpenFOAM were also incorporated to capture midfrequency noise contributions associated with unsteady wake dynamics and blade loading fluctuations. The combined use of mid-fidelity broadband predictions and high-fidelity tonal noise results enables improved reconstruction of the total sound pressure level spectrum and enhances agreement with experimental measurements. Overall, the coupled aerodynamic-acoustic framework provides a robust tool for assessing eVTOL rotor noise across multiple operating conditions and highlights the importance of accurately modelling transitional boundary-layer behavior for reliable broadband noise prediction.

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