Aeroacoustic Predictions of Propeller-Wing-Flap Aerodynamic Interactions using High and Medium Fidelity Simulations

This paper presents a numerical study of aerodynamic noise for propeller-wing-flap configurations. High-fidelity computational fluid dynamics and a medium-fidelity viscous vortex particle method (VVPM) are employed to predict the acoustics of a Clark-Y three-bladed propeller mounted on a tapered half-span wing with a NACA 0015 airfoil. The numerical simulations encompass various thrust conditions, angles of attack (AoA), flap angles, single and dual flap configurations, as well as single and dual propeller configurations. Results indicate that propeller noise dominates at lower harmonic frequencies, while the nacelle contributes predominantly at higher frequencies. Flap deflections do not significantly affect low-frequency tonal noise but increase high-frequency broadband noise. Noise levels increase with AoA, and the first blade passage frequency (BPF) exhibits a positive correlation with thrust. The dualpropeller configuration significantly amplifies tonal noise due to flow interactions between the two propellers. Additionally, trailing-edge noise from propeller blades contributes to significant broadband noise in the high-frequency range. Medium-fidelity predictions align well with high-fidelity results for the first three BPFs especially when a flap is deployed. However, the medium-fidelity model shows a phase lag in the acoustic pressure and the underprediction of wing loading noise. This comprehensive investigation of flap deflections, angles of attack, and thrust conditions highlights the importance of accurate aeroacoustic modeling for future vertical lift concepts and advanced rotorcraft designs.