Numerical Simulation Of Liquid Sloshing In A Two Dimensional Rectangular Tank

Sloshing in tanks is becoming main interest in tank structure design, especially on the development and application of large liquid carries, such as VLCC, LPG and LNG. When the excitation frequency is close to the resonance frequency of the liquid in the partially tank or the excitation amplitudes is very large, the liquid inside a partially filled tank is prone to violent oscillations and then causes violent fluid impacts on tank wall or ceiling with high pressure, which can cause structure damage. Therefore, the liquid sloshing analysis is a very important research topic in the design of liquid carries.Sloshing is a very complex phenomenon of flow with a high degree of nonlinearity and randomness, which is also a typical problem of fluid and structure coupling. The amplitude of the sloshing depends on many factors, such as the frequency and amplitude of excitation, liquid-fill depth, liquid properties and tank geometry, internal components. Based on Finite element software ADINA, sloshing characteristics of viscous liquid in a 2-D rigid and elastic rectangular tank under surge excitation were analyzed. The main jobs of this paper are as follows:(1) First, based on Finite element software ADINA,the numerical model of viscous liquid in a two dimensional rectangular tank under surge excitation were build, then the liquid sloshing natural frequencies of different modes were computed. The numerical model was validated by comparing the free surface elevation with the analytical solution under different conditions.(2) Second, through the numerical simulation, the influences of different excitation amplitudes and frequencies on the liquid sloshing in a two dimensional rigid tank were analyzed, and the free surface elevation and the reaction of liquid sloshing on the wall of the tank were computed.(3) Last, the influences of different thickness of the tank and the excitation frequencies on the liquid sloshing in a two dimensional elastic tank were analyzed, and the sloshing natural frequency, the structure natural frequencies of different modes with water in the tank or not were obtained. The free surface elevation and the structural response characteristics were also discussed, and then based on the Fast Fourier transformation, the frequency analysis is conducted to the free surface elevation and the structural response. The vibration frequency characteristics of different excitation frequency are obtained in both liquid and structure.