Semi-active fluid damper system - Liquid damper column with adjustable properties


Ref.-No. 3741

For over 100 years, so- called TLCD (Tunes Liquid Column Dampers) have been used to reduce vibration in ships and structures. It is a U-shaped tank system filled with a liquid, in which the vibrational energy of the building is converted into heat by turbulence and friction within the fluid. For this purpose, the damper is structurally designed and is matched to the natural frequencies of the building antiphase oscillation of the liquid occurs with optimized damping. Usually such systems are completely passive, which means in their properties and during operation not changeable. If, however, after commissioning, the dynamic properties of the building structure change, which is due to normal aging but also to large oscillation amplitudes, e.g. actually occurs during an earthquake, a passive damper is no longer optimally effective. This leads to an even further increase in the vibration amplitudes. The present technology of a semi- active TLCD solves the problem, in that not only the damping factor, but also the natural frequency of the damper can be dynamically adapted to changing conditions by adjusting the internal geometry of the damper. In combination with corresponding vibration sensors on the structure, which supply the control parameters, it always ensures an optimal effect of the dampers. Due to the adjustability of the vertical tank walls, the natural frequency of the water column oscillation can be changed independently.

Competitive Advantages

  • Adjustable damper frequency
  • Sensor-based control for dynamic Adjustment
  • Optimized damping effect with variable boundary conditions

Commercial Opportunities

For very high buildings and chimneys an effective damping system is absolutely necessary. The technology which is presented here, offers an economic compromise of improved effectiveness, compared to purely passive dampers and moderate costs compared to fully active systems with actuators to produce a targeted counter vibration. Although such systems are even more effective but also very expensive and prone to failure in an emergency. In addition, the growing market for wind turbines offers a promising field of application. The problem of unsatisfactory life expectancy of large onshore and offshore wind turbines can largely be attributed to unsolved vibration problems and the resulting increased wear. At the same time, the application of the semi- active TLCD technology for wind turbines, offers a high saving potential in the static design of the masts, due to the reduction of the fatigue loads.

Current Status

The invention has been applied for patent. Do not hesitate to ask for status details. A proof- of- principle has been provided (see figure above). We are looking for companies interested in the commercial application of the intellectual property rights.


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