摘要
在圆柱腔壁面为声学硬壁面的假定下 ,利用圆柱腔体空间内的格林函数导出了圆柱腔内旋转运动点声源空间声压的近场频域解 ;进而利用该频域解计算分析了旋转简谐单极子点源的声学特性。计算分析表明 :由于考虑了壁面的影响 ,在圆柱腔体内 ,点声源旋转频率和源频率的变化将改变声压的空间指向性 ;源频率和旋转频率的增加伴随明显的多普勒效应 ,同时基频声压沿圆柱腔体轴线的分布从比较平缓变为明显波动 ;沿半径方向基频声压也波动变化。
On the assumption that no sound waves can be transmitted through the wall of a cylindrical cavity, a new expression of Green function is used to deduce the near field acoustic frequency domain solution for a rotating point source in the cylindrical cavity. As an example for application, the rotating monopole point source is assumed to form the simple harmonic motion in a cylindrical cavity and its acoustic performance is obtained. The results show that in the cylindrical cavity, the amplitude of basic frequency sound pressure fluctuates in the radial direction, variations of source frequency and rotating frequency would change the spatial directivity of sound pressure, and with the increase of source frequency and rotating frequency, the Doppler effect appears evident and the distribution shape of basic frequency sound pressure along the axis of the cylindrical cavity changes from relative flatness to obvious fluctuation.
出处
《应用力学学报》
CAS
CSCD
北大核心
2004年第2期37-40,共4页
Chinese Journal of Applied Mechanics
关键词
圆柱腔体
旋转点声源
格林函数
频域解
cylindrical cavity, rotating point source, Green function, frequency domain solution.
