Investigating the Aerodynamic and Aeroacoustic Behavior of a Single Propeller-Wing Configuration in Turbulent Flow

This study experimentally examines how turbulent inflow affects the noise emitted by a single propeller–wing configuration and compares it with that of an isolated propeller in clean flow, using a five-bladed propeller. Tests were conducted at free-stream velocities from 8 to 30 m s−1, corresponding to advance ratios of J = 0.26–1.05. Aerodynamic measurements show that the wing improves propeller performance, increasing thrust and propulsive efficiency across the entire advance-ratio range relative to an isolated propeller. Spectral analysis of baseline SPL reveals that the overall reduction in noise with increasing J is driven mainly by a pronounced decline in broadband energy between the first and third blade-passing frequencies. The propeller–wing system was exposed to both clean flow and three turbulent inflows generated by grids with progressively larger integral length scales and intensities. Turbulence-flow reduces the aerodynamic force coefficients yet preserves the general trend with advance ratio observed in clean flow. Far-field data demonstrate that turbulence-flow markedly increases the overall sound-pressure level (OASPL) at high J. For 0.26 < J < 0.46, the smallest-scale grid produces noise levels indistinguishable from those in clean flow, whereas the two higher-intensity grids introduce only mild broadband increases. Above J ≈ 0.46, all turbulent cases diverge from the baseline, with the highest-intensity grid adding up to 10 dB downstream. These results confirm that low-intensity, small-scale turbulence has little acoustic impact at high advance ratios, whereas larger, more energetic eddies significantly amplify radiated noise.