Acoustic and Mechanical Engineering Laboratory (LEAM), Technical University of Catalonia C/Colom 11, 08222 Terrassa, Spain.
J Acoust Soc Am. 2011 Jul;130(1):239-48. doi: 10.1121/1.3596465.
This paper investigates both theoretically and experimentally the sound radiation from an aperture placed in an enclosure wall for the particular case of low modal sound field. The incidence field is composed of the enclosed sound field, which is calculated using the theoretical modal model presented. The transmitted sound is calculated by the Rayleigh radiation equation after continuity conditions have been applied in the aperture plane, assuming the condition of a thin wall. The model is experimentally validated by measuring the directivity and sound pressure radiated from an aperture in the side of a rectangular box. Because the walls of the enclosure are not rigid, an experimental procedure to determine its admittance is also presented. The experiments have been carried out for the first four modes of the enclosed sound field, and good agreement is found between the theoretical and experimental results. These results indicate that the admittance of the aperture, its radiation efficiency, and its directivity are all functions of the predominant mode shape, and the frequency, as well as the location and shape, of the aperture relative to the predominant enclosed mode shape.
本文从理论和实验两个方面研究了在低模态声场情况下，置于封闭壁上的孔的声辐射。入射场由封闭声场组成，该声场是通过所提出的理论模态模型计算得出的。在孔平面上应用连续性条件后，通过瑞利辐射方程计算出透射声，假设壁是薄的。通过测量矩形盒侧面孔的指向性和辐射声压，对模型进行了实验验证。由于封闭体的壁不是刚性的，因此还提出了一种确定其导纳的实验程序。实验是针对封闭声场的前四个模态进行的，理论和实验结果之间存在很好的一致性。这些结果表明，孔的导纳、辐射效率和指向性都是主导模态形状、频率以及孔相对于主导封闭模态形状的位置和形状的函数。
