Computational aeroacoustics of phonation, Part I: Computational methods and sound generation mechanisms
Computational aeroacoustics of phonation, Part I: Computational methods and sound generation mechanisms
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DOI：
10.1121/1.1506693
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发表时间：
2002-11-01
影响因子：
2.4
通讯作者：
Mongeau, L
中科院分区：
文献类型：
--
作者：
Zhao, W;Zhang, C;Mongeau, L
采用直接数值模拟的方法，研究了带调制孔板的刚性管内气流和声场在发声过程中的气动产生。考虑了壁面运动的强迫振动，忽略了流固耦合作用。用高精度的有限差分方法数值积分了可压缩的二维轴对称形式的Navier-Stokes方程。移动的网格被用来模拟移动的墙的效果。选择几何和流动条件来近似发声时理想的人类声门和声道内的流动。对几种壁面运动程序和流动条件进行了流动和远场声场的直接模拟。然后，基于Ffowcs Williams-Hawking方程的声学类比被用来将声源分解为其单极、偶极和四极贡献进行分析。用声学类比方法预测的远场声压与直接数值模拟的结果吻合较好。结果表明，声门壁表面沿声波传播方向对流体施加的净力所产生的声偶极子是主要的发声机制。在所考虑的频率(125赫兹)下，单极机制，特别是由壁面运动所置换的液体体积发出的声音，被发现是相对较弱的。发现孔口几何形状对辐射声音的幅度只有很小的影响。(C)2002年美国声学学会。
The aerodynamic generation of sound during phonation was studied using direct numerical simulations of the airflow and the sound field in a rigid pipe with a modulated orifice. Forced oscillations with an imposed wall motion were considered, neglecting fluid-structure interactions. The compressible, two-dimensional, axisymmetric form of the Navier-Stokes equations were numerically integrated using highly accurate finite difference methods. A moving grid was used to model the effects of the moving walls. The geometry and flow conditions were selected to approximate the flow within an idealized human glottis and vocal tract during phonation. Direct simulations of the flow and farfield sound were performed for several wall motion programs, and flow conditions. An acoustic analogy based on the Ffowcs Williams-Hawkings equation was then used to decompose the acoustic source into its monopole, dipole, and quadrupole contributions for analysis. The predictions of the farfield acoustic pressure using the acoustic analogy were in excellent agreement with results from the direct numerical simulations. It was found that the dominant sound production mechanism was a dipole induced by the net force exerted by the surfaces of the glottis walls on the fluid along the direction of sound wave propagation. A monopole mechanism, specifically sound from the volume of fluid displaced by the wall motion, was found to be comparatively weak at the frequency considered (125 Hz). The orifice geometry was found to have only a weak influence on the amplitude of the radiated sound. (C) 2002 Acoustical Society of America.