Fluid-structure interaction modelling of internal structures in a sloshing tank subjected to resonance

In this paper we develop a three-dimensional, fully coupled, partitioned-based fluid-structure interaction (FSI) model for liquid sloshing analysis in partially filled containers. Different tank geometries are considered in the present study focusing on both the rigid and flexible baffles and their influence on slosh loads at the tank walls. For the purpose of validation, we develop a stand-alone CFD model and compare the results with the previously existing numerical model and experimental data from the literature. Once such a validation is complete, we incorporate a rigid baffle like obstruction to study the effect of the baffle on sloshing using the stand alone CFD model. The numerical simulations predict that the influence of baffle like obstructions can help in mitigating the tank resonance. Using the standalone CFD model as a base, we develop a FSI model by incorporating the elastic-plastic material properties on the baffle to study the effect of a flexible baffle inside a sloshing tank. A comparative study between the force response of the rigid and flexible baffles during various slosh loads is examined by varying the amplitude of the tank excitation for the same fill level and frequency. The FSI model reveals details on slosh forces experienced by the baffle that are dampened owing to its flexibility. In addition to predicting the forces on the baffle, the FSI model also helps to predict the corresponding nodal displacements and stress states of the baffle under various slosh loads.