Improved prediction of propeller tonal noise through integration of Hanson's model into a modern surface-vorticity panel code

This work aims at improving the precision of tonal noise prediction in urban air mobility (UAM) and general aviation applications, where noise reduction proves essential for vehicle certification and acceptance. To this end, classic acoustic theory is incorporated into a modern surface-vorticity panel code to predict the tonal noise of a benchmark propeller. Central to this research is Hanson's axially symmetric inflow formulation, an approach based on Goldstein's solution to Lighthill's wave equation. Throughout this effort, the accuracy and limitations of the resulting approach are validated using experimental data derived from NASA's Low Speed Aeroacoustic Wind Tunnel. The underlying evaluation enables us to confirm the model's reliability while establishing a basis to assess its efficacy when used in conjunction with a surface-vorticity solver. In this manner, the effective implementation of Hanson's axially symmetric inflow formulation within a modern surface-vorticity panel code is demonstrated. It is also shown to enhance acoustic prediction capabilities while maintaining a computationally efficient workflow. The validation of these models aims to promote further developments of efficient propeller noise prediction techniques including their adoption in early UAM vehicle design. • Integration of Hanson's model into a surface-vorticity panel code is validated experimentally. • Hanson's model circumvents the need to process large sets of acoustic pressure signals. • Frequency-domain analysis of propeller noise at subsonic tip speeds is shown to be sufficiently accurate. • Loading and thickness contributions from propeller blades have the strongest bearing on noise generation. • Propeller torque estimation is shown to have a small effect on noise generation.