基于波数谱的双层圆柱壳外壳振动与声辐射特性分析
Analysis on the vibration and sound radiation characteristics of double cylindrical shells using wave number spectrums
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摘要: 为说明双层圆柱壳外壳振动模式与声辐射间的一般性规律,在通过结构有限元耦合流体边界元方法获得外壳的振动响应后,采用波数谱分析方法将其振动响应在无限长圆柱面上进行波数域的展开,实现振动的波形分离,并获得振动和声辐射功率波数谱,从而对其振动与声辐射模式进行判断。研究表明,双层圆柱壳外壳的周向振动呈现为多模式特征,轴向振动具有短波振动特征;周向辐射模式为低阶辐射模式,轴向辐射模式为长波辐射模式。Abstract: In order to explain the universal rules between the vibrational model and the sound radiation of double cylindrical shells, the coupling vibration responses of the structure are obtained with Finite Element Method combined with Boundary Element Method (FEM/ BEM). Then, the radial vibration on the cylindri-cal coupling surface is transformed into the wave number domain with the wave number analysis spectrum method, which generates the vibration and radiation power spectrums. Next, the vibration and sound radia-tion characteristics are obtained by comparing the vibration power and radiation power associated with each component of regular waves. It is seen that the vibration of outer shell consists of many components in cir-cumference and is dominated by short waves in the axial direction. Meanwhile, the sound radiation is domi-nated by low order vibration components in circumference and long waves in the axial direction.