Tuned liquid dampers

Tuned liquid dampers (TLDs) are increasingly being used as dynamic vibration
absorbers to minimize the vibration of structures. A tuned liquid damper is a tank filled
with a liquid. When attached to a structure, the liquid sloshing action inside the TLD
dampens and absorbs part of the energy given to the structure. The difficulty in designing
TLDs arises from its nonlinear response (behavior), which requires a detailed
understanding of the sloshing motion inside the TLD. An in-house numerical algorithm
has been developed to investigate and understand liquid sloshing motion inside TLDs and
to evaluate the TLD damping performance when coupled with a vibrating Single Degree
of Freedom (SDOF) structure. The model is based on the finite-difference method. The
Volume of Fluid method has been used to reconstruct the liquid free surface. The
Continuum Surface Force model has been used to model and resolve the discontinuity
accompanied with wave breaking that might take place at the liquid surface. All dynamic
stresses on the free surface have been taken into consideration to evaluate wave breaking.
No linearization assumptions have been used in solving the Navier-Stokes equations. The
developed numerical model incorporates the interaction between the structure dynamics
and the TLD. In this study, the structure has been assumed as a SDOF system and its
dynamic response has been calculated using the Duhamel integral method.
The model has been validated against experimental data with and without the
structure. Good agreement was obtained between the numerical and the experimental
results.