点声源入射下无限大平板的隔声

Sound insulation of an infinite partition subject to a point source incidence

利用球面波的平面波展开形式,推导了自由场中点声源入射下无限大平板的隔声公式,研究了其隔声性能。数值模拟结果表明,点声源入射下平板隔声规律不同于通常采用的平面波入射条件下的质量隔声定律。在频率较低或板厚度较薄时,频率或板面密度增加一倍,平板隔声量的增加约为3 dB,而插入损失的增加约为6 dB。

By using plane wave integral representation for the spherical wave, the sound insulation performance of an infinite partition subject to a point source incidence in a free field is investigated with theoretical analysis and computer simulations. The numerical simulations show that the sound insulation based on a point source incidence doesn＇t follow the mass law which is obtained based on plane wave incidence. The transmission loss increases by about 3 dB and the insert loss increases by about 6 dB as the frequency or the surface density doubles for a thin partition at low frequencies.