Effect of a vertical baffle on the resonant steady-state sloshing impacts in a square-base container with longitudinal harmonic excitations

Three-dimensional (3D) resonant liquid sloshing is experimentally investigated in a square-base container with and without a vertical baffle subjected to harmonic horizontal forcing. This study aims to understand the influence of baffle height on the sloshing response, including viscous damping, natural frequency, frequency ranges of different wave modes, wave profiles, and impact pressures on the sidewall and roof. A relatively large liquid depth and three different vertical baffles with varying heights are considered. To elucidate the experimental observations, a potential-based analytical solution for natural sloshing modes and an asymptotic modal system for the frequency ranges of wave modes are employed. Theoretically, four types of sloshing wave modes exist, i.e., planar standing, diagonal standing, regular rotating, and irregular chaotic wave modes, for a clean container. However, diagonal standing waves are difficult to experimentally observe because their effective frequency domain coincides then with those for the planar ones. Therefore, the other three wave modes are focused on herein. When the amplitude of the rotating and chaotic waves is large, the corner of the roof experiences extremely high impact pressures. Consequently, the frequency ranges of rotating and chaotic waves evidently decrease with increasing baffle height. Furthermore, the sloshing wave amplitude and maximum impact pressure at the roof decreases due to the suppression effects of the baffle.