基于虚拟双全息面的声场分离方法研究

The Study on Sound Field Separation Method Based on Virtual Double Holographic Surface

为了能在噪声源的辐射声和反射声形成的混合声场中使用标准的近场声全息技术,本文提出基于虚拟双全息面声场分离方法。该方法采用虚源理论,将反射声看成是由噪声源的虚源产生的辐射波,通过将全息面向远离声源的方向移动微小距离从而形成虚拟全息面,全息面和虚拟全息面的声压采用球面波方法分离出目标噪声源产生的辐射声。达到虚拟出目标噪声源的声自由场的目的,进而采用传统的近场声全息的方法重构声源。用脉动球进行仿真,仿真的结果表明采用基于虚拟双全息面的声场分离方法能非常有效地消除声场中的反射声的影响。仿真对测点间距和虚拟全息面的距离对声场分离的影响进行了研究,并给出了最佳的测点间距和最佳的虚拟全息面距离。

In order to achieve the sound free field condition used by the near-field acoustic holography tech-nology, this paper proposes a sound field separation method based on the virtual double holo-graphic surface. This method bases on the virtual source theory and regards the reflected sound as a radiation wave generated by a virtual source formed by reflective material. The virtual holo-graphic surface is formed by moving the holographic surface away from the sound source by a cer-tain distance. Then the spherical wave method is used to separate the sound field. In this way, the acoustic free field is virtualized, and the traditional near-field acoustic holography method can be used to reconstruct the sound source. A pulsating sphere is used for simulation, and the results of the simulation show that the sound field separation method based on the virtual double holograph-ic surface can effectively remove the influence of the reflected sound in the sound field. The simula-tion studies the influence of the distance between the measuring points and the distance between the holographic surface and the virtual holographic surface, and gives the best distance between the measuring points and the best distance between the holographic surface and the virtual holo-graphic surface.