An Acoustic Black Hole Effect-Based Sound Barrier Structure Applied to Urban Substations

The proliferation of urban substations situated near residential areas has intensified the need for effective noise control, particularly in the mid-to-high frequency range. Traditional sound barriers often rely on mass-increasing strategies, which are constrained by the mass law and practical installation limitations. This study investigates a lightweight sound barrier solution utilizing an embedded Acoustic Black Hole (ABH) structure to address this challenge. Numerical simulations predict a significant improvement in the Sound Transmission Loss (STL) of the ABH plate compared to uniform plates. Experimental validation conducted in a specific cavity setup demonstrates that the damped ABH plate (2.97 mm thick, 3.47 kg) achieves a superior noise reduction performance, matching or even exceeding that of a significantly heavier uniform plate (4 mm thick, 5.00 kg) above its characteristic frequency (254 Hz), while realizing a 30% weight reduction. The superior performance is explained by two synergistic mechanisms: the ABH’s power-law profile concentrates bending wave energy for highly efficient damping at the thin tip; it compresses the structural wavelength, reducing radiation efficiency synchronously. The findings confirm the ABH structure as a promising, lightweight technology for controlling substation equipment noise, with broad application prospects in urban acoustic environmental protection.