An experimental investigation is conducted on the effects of vertical baffles on resonant sloshing at the internal surface in a two-dimensional (2D) rectangular tank filled with two immiscible liquids. This work established three experimental devices with different oil–water height ratios to explore the inhibitory effect of baffles and the number of baffles on internal surface resonant sloshing. Special attention is given to the internal surface wave amplitudes at the first mode, third mode, and fifth mode resonant conditions of the internal surface. Experimental findings reveal that at the first mode resonant condition of the internal surface, the presence of vertical baffles significantly suppress internal surface sloshing amplitudes, where the suppression effect exhibits a linear relationship with baffle quantity. At the resonant condition of the third mode, the influence of baffles on the internal surface motion has no certain regularity. Under the fifth mode resonant condition, the introduction of vertical baffles conversely enhances internal surface wave amplitude. In addition, the influence of the number of baffles on the internal surface sloshing is independent of changes in the oil-water height ratio.
Chang et al. (2025) studied this question.