Interaction of Edgewise Transient Disturbance with a Propeller

This study investigates the aerodynamic and acoustic responses of a scaled propeller subjected to an edgewise transient disturbance. High-fidelity simulations are performed using a hybrid LES-URANS (DES) approach, and far-field noise predictions are obtained via the Ffowcs Williams–Hawkings (FW-H) formulation. The numerical results are validated against experimental data for both transient disturbance ingestion and propeller performance under uniform inflow. During disturbance interaction, the propeller experiences a temporary decrease in thrust and a corresponding increase in torque—both by approximately 2%—attributed to disturbance-induced variations in local vorticity and blade surface velocity fields. Analysis of the dilatation field and surface pressure fluctuations reveals that the transient disturbance reduces acoustic emissions. The root mean square (RMS) of the pressure fluctuations confirms that this reduction is closely associated with blade–wake interaction (BWI) noise. Far-field acoustic analysis using Sound Exposure Level (SEL) and time-resolved spectrograms shows a clear reduction in low-to-mid frequency noise—typically linked to blade–vortex interaction (BVI) and blade–wake interaction (BWI) mechanisms—during the gust interaction. A modest post-disturbance increase in mid-frequency noise is observed, attributed to stronger wake formed by the slightly asymmetric trailing edge of the wing as it returns to its original position.