Energy dissipation in violent three-dimensional sloshing flows induced by high-frequency vertical accelerations

The European H2020 project SLOWD is aimed to investigate the fuel sloshing damping effect to reduce the design loads on aircraft wings. Wings house the fuel tanks and are highly flexible structures that can significantly deform under gust loads. In the recent experiment by Martinez-Carrascal and Gonzalez-Gutierrez [ "Experimental study of the liquid damping effects on a SDOF vertical sloshing tank, " J. Fluids Struct. 100, 103172 (2021)], the complex problem of the fuel sloshing inside a flexible wing structure was significantly simplified by considering a partially filled vertically heaving tank attached to a system of springs. In the present research, a smoothed particle hydrodynamic model was adopted to evaluate the energy dissipated in the three-dimensional sloshing flow obtained using the same tank motions. From a numerical point of view, the simulation of such a violent flow is rather challenging, the involved vertical accelerations being as large as 10 g. The resulting flow is extremely complex because of the severe turbulence developed, the violent impacts, and the considerable fragmentation of the air-liquid interface. The role of the viscosity is investigated by taking into account two different liquids. Finally, some comparisons between three-dimensional results and previous two-dimensional studies are also discussed. Published under an exclusive license by AIP Publishing.