Analysis of damping from vertical sloshing in a SDOF system

The effect of the sloshing motion liquid in a tank on vertical transient single degree freedom system is investigated. Step release tests vertically vibrating structure, including containing liquid, demonstrate that added damping from depends upon amount fluid and maximum acceleration. was observed at 50% fill level showed three distinct response regimes during decay, all related to different motions fluid. first regime, immediately start transient, considered be most important exploit for aircraft gust loads alleviation due its dominant role overall energy dissipation balance. Further, advance understanding modelling predictive capabilities, coupled fluid-structure models two opposing levels fidelity were developed evaluated. Namely, smoothed particle hydrodynamics (SPH) an equivalent mechanical model (EMM) based bouncing ball represent experiment. Both are shown provide good capability initial impacting mode while subsequent flow regime can predicted with SPH only. findings this paper open routes towards improved their use aeroelastic wing design.