Study of the Aerodynamic Characteristics and Interaction Noise of Airfoil with Porous Leading Edges Based on the Rod-Airfoil Model

To investigate the suppression effects of porous materials on turbulence interference noise at the leading edge of airfoils and reveal the noise reduction mechanism, numerical simulations of the classic rod-airfoil (NACA0012) interaction noise model were conducted using Large Eddy Simulation (LES) combined with the FW-H acoustic analogy method. The numerical setup was validated via experimental data comparison and grid sensitivity analysis. This study compared the flow field and sound field characteristics of a solid leading edge and porous leading edges with porosities of 40%, 50%, and 60%, respectively. The results showed that porous leading edges could effectively attenuate low- and mid-frequency single-tone noise, and the noise reduction performance improved as porosity increased. A maximum noise reduction of up to 11.2 dB was achieved, yet the average drag also rose correspondingly. Analyses of pressure fluctuations, velocity distribution within the stagnation region, and turbulent coherence were also performed. The results indicated that the porous medium suppressed the vertical velocity component of the incoming flow as the flow impinged on the leading edge; consequently, the pressure fluctuations were also suppressed. Furthermore, the porous structure disrupted the spanwise coherence of turbulent structures and weakened acoustic radiation efficiency.