Objectives  The free and forced vibration characteristics of a horizontal fluid-filled cylindrical shell and the fluid inside the shell are studied based on the finite element method.

  Methods  The structure and fluid are simulated by shell elements and acoustic elements respectively. A gravity acceleration is applied to the fluid acoustic element and the free liquid surface is marked, so simulate small amplitude sloshing of the fluid. The sloshing frequencies of fluid and shell vibration frequencies are calculated and are also compared with published results, to verify the correctness of the solution method. The influence of the structural parameter and free liquid surface height on the coupled system vibration characteristics is examined.

  Results  The results show that the natural frequencies of the fluid include high frequency and low frequency. The low frequency is the natural sloshing frequency of free liquid surface corresponding to the sloshing mode of the free surface. The thinner the shell thickness, the lower the frequency of the structure coupling and the natural sloshing frequency of the free liquid surface. The sloshing frequencies approach the value under the rigid boundary with increasing of the shell thickness. The greater the liquid depth, the lower the frequency of the structure coupling and the greater the natural sloshing frequency. The impact of the sloshing effect of the free liquid surface on response of the coupled system becomes significant when the structure frequency is very low.

  Conclusions  The results have a reference value for the vibration characteristics of fluid-filled cylindrical shell.