空间分布系列球壳声场耦合与辐射特性研究

Acoustic field coupling and radiation characteristics of spatially-distributed spherical shells

针对大深度载人潜器的多球壳组合结构,以水介质中任意空间分布的系列弹性球壳为研究对象,利用球函数平移加法定理,建立计及球壳间声场相互作用的多球壳系统声振耦合模型,计算分析空间分布系列球壳的声场耦合特性及其影响因素。结果表明:声场相互作用将改变球壳模态间耦合关系,使得单阶模态对球壳振动的贡献不再限于单个峰值,进而影响声辐射频谱特征;双球壳系统受激球壳和非受激球壳都产生声辐射,轴向激励情况下,两球壳间存在强声场耦合效应,激励力偏离轴向时,声场耦合效应逐渐减弱;不同尺度球壳组成的双球壳系统扩展了声场有效耦合的频率范围,辐射声场兼具两个球壳的模态特征;多球壳串列布置时,声场耦合效应具有传递作用,多球壳按不同角度分散布置时,辐射声场空间分布则更趋复杂。

The multi-spherical shells composite structure is a common structurural form of manned submers‐ibles.A vibro-acoustic coupling model of multi-spherical shells system considering acoustic field coupling between shells was established by using the translationnal addition theorem for spherical wave function.The acoustic field coupling characteristics and their influencing factors of a series of spatially-distributed spheri‐cal shells were studied.The results show that the acoustic field interaction can change the coupling between the modes of the spherical shells.The contribution of a single mode to the vibration of the spherical shell is no longer limited to a single peak,and thus affects the spectral characteristics of the acoustic radiation.Both shells of the double spherical shells system generate acoustic radiation.There is a strong field coupling effect between two spherical shells under axial excitation.When the excitation force deviates from the axial direc‐tion,the field coupling effect gradually weakens.The double spherical shells system composed of spherical shells with different scales expands the frequency range of effective coupling,and the modal characteristics of both shells appear in the acoustic field.When the spherical shells are arranged in series,the acoustic field coupling has a transmission effect.While the spherical shells are distributed at different angles,the spatial distribution of acoustic field becomes more complex.