中文摘要：

以往的文献在分析流场中圆柱壳的声振特性时,往往将流场简化为理想状态,忽略了粘性的影响。以浸没在粘性流场中的无限长弹性薄圆柱壳为研究对象,研究了流体粘性对频散特性的影响规律。首先,分别用Flügge薄壳理论和势函数方法分析壳体结构振动和外部流体声场。然后,通过壳壁外表面的运动协调条件,建立此耦合系统的声振耦合方程,进而采用Winding-Number围线积分法搜索求根,重点求取和分析了粘性流场中无限长弹性薄圆柱壳的频散曲线,并与理想流体中的特性作了对比,得出了一些有价值的结论,有助于理解粘性的影响及程度。

英文摘要：

The effect of fluid viscosity on the vibration dispersion characteristics of an infinite circular cylindrical shell immersed in a viscous acoustic medium is studied.The Flügge＇s thin shell theory for the isotropic,elastic and thin cylindrical shell,the wave equation for viscous flow field derived from the linear equations of continuity,Navier-Stokes and state and the appropriate wave-harmonic field expansions along with the pertinent boundary conditions are employed to obtain the equations of motion and the dispersion equation in the coupled system.Subsequently,Numerical analysis is applied to solve the dispersion equation for the shell loaded with fluid at various viscosity coefficients.Then the dispersion characteristic curves,the Amplitude ratio curves of complex waves and the relative error parameter curves of non-dimensional axial wave numberλin the coupled system under different circumferential modals are displayed in several figures.It can be found from the figures that the influence of fluid viscosity on the dispersion characteristics of the propagating waves is more significant at low frequency range,while the variation tendency of the curves is nearly independent.As for the complex waves,the amount and cut-off frequency of the waves in the coupled system are proportional to the fluid viscosity coefficients.