声学二维平面周期结构的吸声性能建模

声学周期结构兼具优化室内声场环境,节约建筑吸声材料的特性而在现代建筑中广泛使用。针对二维平面周期结构的声场优化特性,建立了一种吸声系数计算模型。首先,根据边界条件理论推导了吸声系数的线性方程组,继而通过数值分析方法进行求解,最后在驻波管和混响室中分别进行实验验证。实验结果表明,测量的吸声系数和理论计算曲线吻合良好,该模型可以准确测算二维平面周期结构的吸声系数。同时分析表明:在平面周期结构中,相同吸声材料面积情况下,吸声材料占比越大,吸声效果越好;在相同吸声材料面积和占比情况下,材料边缘长度越长,高频段吸声效果越好;随着材料边缘长度的减少,边缘效应影响减弱。 

Simulation model of sound absorption of two-dimensional periodic flat surface

The periodically arranged acoustical structures are commonly used in the modern architectures as they can improve the acoustical environment while decreasing the demand for the absorptive materials. In order to investigate the acoustic characteristics of the two-dimensional periodic flat surface, a simulation model of sound absorption is established. First of all, the linear system of equations of the sound absorption coefficients is theoretically deduced based on the boundary condition. Then the equations are solved by numerical analysis. Finally, experiments in both the Kundt's tube and the reverberation chamber are carried out to verify the theory. The experimental results fit the calculated curves well. It is shown that by utilizing this simulation model, a good prediction of sound absorption of the two-dimensional periodic flat surface can be obtained. Besides, data analysis shows that in the periodic structure, with the same area of the absorber, the larger the ratio of the absorber is, the higher the sound absorption coefficient will be; with the same area and the same ratio of the absorber, the longer the length of the edge is, the higher the sound absorption coefficient in the high frequency range will be; with the decrease of the length of the edge, the edge effect will decline.