Impact of baffle flexibility on sloshing mitigation: A parametric study using partitioned two-way fluid-structure interaction

This study investigates liquid sloshing in a rectangular tank equipped with horizontal flexible baffles to understand their influence on sloshing mitigation and intricate fluid-structure interaction (FSI) phenomena. A two-way coupled FSI model was developed using the Finite Element Method (FEM) for structural analysis and Finite Volume Method (FVM) with the Volume Of Fluid (VOF) formulation for fluid dynamics, employing a partitioned coupling strategy. Numerical decay tests explored dynamic behavior by varying baffle Young’s modulus and submergence levels. Enstrophy evolution was investigated as a robust indicator for quantifying energy dissipation associated with vortex dynamics, and a reduced-order acoustic-structural model was benchmarked as a tool for predicting fundamental frequency shifts. The FSI simulation methodology was validated against experimental results from previous literature, showing close agreement. Key outcomes reveal that baffle stiffness critically governs system response, with appropriate flexibility significantly enhancing damping performance. For submerged baffles, increasing flexibility led to optimal damping driven by maximal vortex-induced energy loss. Conversely, shallow baffles showed superior damping with rigid configurations, primarily due to pressure drag rather than vortex dynamics. While initial conditions introduced transient nonlinearities with flexible baffles, overall trends for damping and frequency remained consistent. The simplified frequency-prediction model was reliable for practical flexibility ranges, but less accurate for extreme flexibility. Overall, this work deepens understanding of how baffle characteristics influence slosh mitigation, offering valuable guidance for anti-sloshing device engineering.