Colloquium: Donato Melpignano (FPT)

This thesis investigates the aerodynamic and acoustic performance of Boundary Layer Ingesting (BLI) propellers. Focusing on a rear-fuselage installed propeller, the study examines the effects of non-uniform inflow on unsteady blade loading, performance, and noise emissions. An Unsteady Non-Linear Vortex Lattice Method was developed for aerodynamic modeling, while Hanson's Helicoidal Surface Theory addressed acoustic effects. Due to numerical solver limitations, the model was scaled as real conditions could not be simulated. Results show that BLI configurations enhance thrust-to-power ratios despite in-plane forces and oscillations in thrust and power delivery caused by unsteady blade loading. Noise levels increased due to unsteady loading sources. Adding blades reduced performance oscillations but not unsteady loading noise contributions, while backward sweep effectively reduced them. The findings highlight the sensitivity of noise emissions to propeller geometry and operating conditions.

Supervisor: Tomas Sinnige