Aeroacoustic Installation Effects on a Propeller-Driven Strut-Braced Wing Aircraft

The strut-braced wing (SBW) is a promising design for reducing aircraft emissions. However, the integration with propellers introduces complex aerodynamic and aeroacoustic interactions. This study investigates the aerodynamic installation effects of a propeller-driven SBW aircraft in high-lift conditions. High-fidelity numerical simulations are carried out using a very-large eddy simulation approach coupled with a lattice Boltzmann solver. Two propeller rotation configurations are analyzed: clockwise and counterclockwise. The aeroacoustic analysis is conducted using a hybrid CFD/CAA approach based on the Ffowcs Williams–Hawkings analogy. The propeller slipstream alters the wing loading, reducing aerodynamic efficiency by approximately 7–8% compared to the propeller-off configuration. New insights are provided into the role of the nacelle in modifying the wing loading. Aerodynamic efficiency benefits are found on the strut, experiencing a 21–25% lift increase with minimal drag impact caused by the slipstream. The blade loading exhibits asymmetry due to wing-induced upwash, amplifying tonal noise components at harmonics of the blade passing frequency. The effects of propeller wake impingement on both the wing and strut are analyzed, highlighting distinct interaction mechanisms and their implications on unsteady surface pressure. The noise footprint at certification locations for the outboard-up configuration is 4 EPNdB lower than that of the inboard-up case. This is because, when the blade moves downward on the inboard side, the fuselage blocks the sound waves from the propeller blades, creating a shadow region beneath the aircraft. These findings highlight the importance of component positioning in aircraft design to reduce far-field noise emissions.