Energy analysis of water impact of an elastic cylindrical shell

Water impact of a cylindrical shell is a typical Hydroelasticity problem. The process of this fluid and structure coupling depends on the deflection of the cylindrical shell and the flow field under the shell. This paper investigates the water impact on the cylindrical shell by fluid-structure interaction using a finite-volume method (FVM) for the flow field and a finite-element method (FEM) for the shell structure. Computations are compared with the experimental data to validate the methodology. The water impact process is divided into three stages - energy input, energy oscillation, and energy dissipation by considering the energy variation of the structure and the fluid. Combining the flow field and structural deformation in different stages, this paper analyzes the whole process of water impact both at macroscopic and microscopic levels. During the energy input stage, due to the force of water impact, the structure experiences the elastic deformation; the kinetic energy decreases, the elastic potential energy increases but the free surface is not affected. During the energy oscillation stage, the elastic potential energy and the kinetic energy of the fluid exchange with each other creating oscillations and the free surface moves. During the energy dissipation stage, with the increasing water impact, there is maximum elastic deformation of the structure and the kinetic energy of the fluid decreases.