Analysis of the Noise Reduction of Low-Height Porous Absorptive Barrier in Urban Rail Transit

In this paper, acoustic FEM, acoustic BEM, and acoustic phenomenon model of porous materials are combined to analyze the influence of the geometry parameters and absorptive character of low-height sound barrier on its acoustic insertion loss. For the standard field points, the closer the sound barrier is to the rail, the higher the sound barrier, lead to the greater acoustic insertion loss of the sound barrier. Compared with the higher sound barrier, low-height trackside sound barrier has less insertion loss at the lower near-field point. For higher near-field points, compared with higher sound barriers, the non-absorbing trackside sound barriers can achieve equivalent acoustic insertion loss. For the far-field point, the insertion loss of the trackside sound barrier is equivalent to that of the higher sound barrier. The absorptive structure can improve the acoustic insertion loss, but the enhancement of the insertion loss of the high sound barrier is greater than that of the low-height trackside sound barrier.