Experiments on non-resonant sloshing in a rectangular tank with large amplitude lateral oscillation

摘要

Flow of two dimensional nonlinear sloshing in a rigid rectangular tank with free surface is considered. The flow is generated by oscillating the container in a lateral harmonic motion, i.e., d* = A* sin(2πf*t*) where d* denotes the displacement of the container externally forced, A* the amplitude of displacement and/ the frequency. Thus, the maximum stroke, S*, of the container for a cycle, measured by a distance from the leftmost to the rightmost location on the container movement, is defined as S* = 2A*. It has performed a sequence of experiments on a variety of S*- and f*-values to investigate large amplitude sloshing flows at off-resonant condition far from the system natural frequency, where large amplitude means that the stroke, S*, of the container movement is comparable with the breadth, L', of the container, i.e., S*/L*～O(1) and the excitation acceleration is also comparable with the gravity, i.e., π~2(S*f*)~2/g*～O(1). Through PIV experiment, it shows that the flow physics on nonlinear off-resonant sloshing problem can be characterized into a combination of three peculiar sloshing motions: (1) standing wave motions which is similar with those of linear sloshing during run-down process, (2) run-up phenomenon like hydraulic jump along the vertical sidewall at the moment of turn-around of the container and (3) gradually propagating bore motion from one sidewall to the opposite wall which is similar with dam breaking problem.