流动介质中板状结构辐射声功率研究

Study on Sound Power Radiated by Planar Structures in Moving Media

由对流波动方程和欧拉方程,本文推导了流动介质中区分传播波和倏逝波的辐射椭圆方程及板状结构辐射声功率计算公式。基于该公式,通过提取辐射椭圆内的传播波波数对应的表面法向振速波数域频谱,可实现流动介质中板状结构辐射声功率的计算。基于辐射椭圆方程,明确了介质流动对板状结构辐射声功率产生影响的机理。最后,以简支板为对象,通过数值仿真对比了不同流速下的辐射声功率,结果表明了考虑介质流动影响的必要性及其对声功率的影响规律。

Based on the convective wave equation and Euler equation,this paper derives the radiation ellipse for distinguishing propagating waves and evanescent waves,as well as the formula for calculating the radiation sound power of planar structures in moving media.Based on this formula,the calculation of radiated sound power from planar structures in moving media can be achieved by extracting the wavenumber domain spectrum of surface nor-mal velocity within the radiation ellipse.Based on the radiation ellipse equation,the mechanism of the influence of moving medium on the radiated sound power of planar structures is clarified.Finally,taking a simply supported plate as the object,the radiated sound power under different moving velocities is compared through numerical sim-ulation.The results show the necessity of considering the influence of moving medium and its impact on sound power.