Abstract: [Objectives] Study the liquid sloshing in a rectangular tank under random excitation.
[Methods] The numerical model was established by using computational fluid dynamics (CFD) method, and the reliability of the numerical model validated by comparing with the analytical solution of linear potential flow, experimental data and CFD numerical solution. On this basis, the effects of different peak frequencies of the excitation spectrum and meaningful excitation amplitudes on liquid sloshing are studied.
[Results] The transient effect of random excitation has a significant influence on the fluctuation of free water surface of liquid sloshing in tank and by applying buffer function, stable results can be obtained quickly. When the peak frequency of excitation spectrum is close to the natural frequency of tank , the energy of wave-height response spectrum of liquid sloshing in tank is mainly concentrated at the natural frequency of tank. When the peak frequency of the excitation spectrum is far away from the natural frequency of the tank, the energy of wave-height response spectrum of the liquid sloshing in tank is concentrated near the peak frequency. With the increase of the meaningful amplitude of the excitation spectrum, the amplitude deviation of the liquid sloshing response increases, and the nonlinearity of the tank increases significantly.
[Conclusions] For the simulation of random excitation, especially when the excitation frequency is far away from the natural frequency, it is necessary to buffer the excitation duration. It is found that when the peak frequency of excitation spectrum moves away from the first natural frequency to higher frequencies, the energy is dominant at the ith order natural frequency when the peak frequency is close to the ith order natural frequency.