Comparative assessment of force models for two-dimensional hydrodynamic sloshing in rectangular tanks under horizontal excitation

Sloshing dynamics in tanks represent a complex free-surface flow phenomenon, particularly significant when assessing hydrodynamic forces. Accurate modelling of dynamic processes under varying excitation conditions is essential for capturing sloshing behaviour. In partially filled rectangular tanks, excitation amplitude and frequency are the primary factors influencing the development of sloshing forces. Near resonance, sloshing forces exhibit nonlinear characteristics, including wave formation and breaking, which challenge the fidelity of  conventional analytical and empirical models. This study investigates various modelling techniques to evaluate sloshing forces in partially filled rectangular tanks subjected to horizontal excitation. The models are validated using benchmark experimental data from shaking-table tests. Analytical, semi-analytical, and computational fluid dynamics (CFD) models are compared in terms of complexity and their ability to describe hydrodynamic behaviour. The selected models offer both quantitative and qualitative assessments of sloshing forces under resonance and near-resonance excitations. Results highlight model-specific performances and limitations for case-dependent selection, informed by the broader set of models evaluated. The objective of this study is to assess model quality for sloshing force characterisation within the context of nonlinear wave dynamics and sloshing damper applications.