不同流场中双层圆柱壳层间声振传递特性研究

采用解析法研究了不同流场中双层圆柱壳层间声振传递特性。壳体的振动用Flügge壳体方程描述,将加强构件等价为对内外壳体的支持力,最后求解双壳体声—流体—结构耦合方程,计算结果用表面振动均方速度级、辐射声功率和辐射效率的形式表示。在数值分析部分,讨论了有限长双层圆柱壳壳间连接形式的变化、壳间及外部流场的变化对其声辐射性能的影响,得到结论是在中低频段,当内壳受激振动,通过外壳向外场辐射噪声时,其主要通道为连接内外壳壳体的实肋板,其次才是环形流场中的流体介质。

Sound and Vibration Transmission Characteristics Between Inner and Outer Double Cylindrical Shells in Different Flow Fields

The sound and vibration transmission characteristics between double cylindrical shells in dif-ferent flow fields were studied with the analytical method.The Flügge equation of thin shell was applied to describe the shell vibration.By this equation,stiffening member was usually regarded as equivalent supporting force to the double cylindrical shell,and then the solution of coupled equation of sound-flu-id-structure interaction was obtained.The calculated results were presented in terms of surface vibration mean-square velocity stage,radiation sound power and radiation efficiency.In the numerical analysis,the influences of connection variation between finite-length double cylindrical shells and varied flow fields of outside on the acoustic radiation performances were analyzed.The results show that in the event of the vibration noise excited by inner shell in the low or medium frequency range,the radiated noise of transmission path into the flow field of outside is mainly via the solid plates connected inner and outer shells other than the fluid medium in the annular flow field.