Preliminary numerical modelling of a tuned liquid damper with limited freeboard

A tuned liquid damper (TLD) is often used to mitigate the wind-induced vibrations of tall slender structures. A TLD typically consists of a partially filled rigid water tank located near the top of a structure and is often equipped with screens or devices to increase energy dissipation. The required freeboard for the TLD tank is determined by calculating the maximum sloshing wave height and ensuring sufficient space such that the water does not impact the roof of the tank. A TLD tank designed such that the water can impact the roof would reduce the space required in the structure. To implement a TLD with limited freeboard for a structure, it is necessary to understand the effect that limiting the freeboard has on numerical modelling, TLD performance, and structural tank design. This paper discusses preliminary research on numerical modelling of a TLD with limited freeboard and sloshing water impact with the tank roof. A smoothed particle hydrodynamics (SPH) model is implemented to study a TLD equipped with slat screens for both unlimited and limited freeboard. A comparison between the results of each case is presented. The limited freeboard case is observed to potentially reduce the higher sloshing modes in the tank. Significant spikes in pressure on the tank boundaries are observed for the limited freeboard case. A comparison to existing numerical models shows differences in the magnitude of sloshing response. Refining the treatment of the slat screens in the SPH model may provide improved agreement with existing models.