On wave breaking in tuned liquid dampers

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.

Tuned Liquid Dampers (TLDs) are passive damping devices used to damp vibration due to wind in tall buildings and due to sea waves in offshore platforms. This paper pre-sents numerical results of wave breaking in TLDs obtained using a numerical model developed in-house. The model solves the full form of Navier-Stokes equations for viscous liquid sloshing and handles the moving free surface by using the volume of fluid method (VOF). Some of the previous numerical models invoke a two-phase flow model in con-junction with the VOF method to simulate the wave trans-formation and wave breaking in shallow water. However, these two-phase flow models give no account to the effect of body force on the free surface. The current model uses the continuum surface force model (CSF) which models the discontinuity accompanied with wave breaking as a con-tinuous transition where fluid properties such as density vary smoothly from one fluid to another. Numerous experi-mental studies reveal that the impulse pressure exerted on the tank walls varies in a similar nature as that of the applied excitation. Accordingly, the current numerical model sug-gests new formulae for the pressure at the left and right TLD walls. The present numerical results are in good agreement with experimental data. The current model is able to accu-rately detect surface wave breaking at various excitation frequencies.