Sloshing poses significant risks to the structural integrity, stability, and maneuverability of marine vessels. This study employs an enhanced moving particle semi-implicit method to investigate sloshing in a partially filled tank equipped with a constrained floating baffle. The baffle length ratio Lb/L is varied from 0 to 0.6, and the free-surface elevation, wall pressure, and tank lateral force are examined from the initial transient to the quasi-steady regime. Power spectral density, phase-resolved vorticity fields, and energy histories are further analyzed to characterize the dominant-mode response and the underlying dissipation mechanisms. The results reveal a nonlinear saturation with increasing baffle length: the primary resonant response decreases markedly as Lb/L increases. However, under the present excitation and filling conditions, when Lb/L reaches a certain range of approximately 0.45–0.55, the marginal suppression becomes limited, indicating a threshold-like behavior in the mitigation effect of the constrained floating baffle. The mechanistic evidence indicates that the baffle enhances localized shear and vortex activity in its vicinity, causing vortex interaction and breakup during flow reversal and thereby weakening the phase-coherent momentum feedback that sustains the primary sloshing mode. Consequently, both the dominant spectral component and the impact-related pressure fluctuations are reduced, leading to lower hydrodynamic loads. These findings clarify the dissipation mechanism of constrained floating baffles and provide useful guidance for anti-sloshing design in partially filled tanks.
Wu et al. (Mon,) studied this question.