• Title/Summary/Keyword: Tuned Liquid Column Damper

Search Result 44, Processing Time 0.026 seconds

Motion analysis of a VLCO for wave power generation (파력발전용 가변수주진동장치의 운동해석)

  • Lee, Seung-Chul;Goo, Ja-Sam
    • Journal of Power System Engineering
    • /
    • v.18 no.3
    • /
    • pp.36-41
    • /
    • 2014
  • The structure of a variable liquid column oscillator(a VLCO) is analogous to that of the tuned liquid column damper used to suppress oscillatory motion in large structures like tall buildings and cargo ships. The VLCO is a system absorbing high kinetic energy of accelerated motions of the multiple floating bodies in the effect of air springs occurred by installation of inner air chambers. Thus, VLCO can improve the efficiency of energy than wave energy converters of the activating object type made in Pelamis Company. In this research, the experiment was performed in two models of same draft. The one is that weights were filled, and the other is that water was filled. The numerical results were estimated by assuming that do not exist internal flow, and the results were compared with the results of experiments.

Optimal Design Parameters of Multiple Tuned Liquid Column Dampers for a 76-Story Benchmark Building (76층 벤치마크 건물에 설치된 다중 동조 액체 기둥 감쇠기의 최적 설계 변수)

  • 김형섭;민경원;김홍진;이상현;안상경
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2004.04a
    • /
    • pp.251-258
    • /
    • 2004
  • This paper presents the parameter study of multiple tuned liquid damper (MTLCD) applied to the 76-story benchmark building. A parameter study involves the effects of number of TLCD, frequency range, and central tuning frequency ratio, which are important parameters of MTLCD. The performance of MTLCD is carried out numerical analysis which reflects the nonlinear property of liquid motion. The parameters of TLCD exist different each optimal values according to mass ratio. The performance of single-TLCD (STLCD) is sensitive for tuning frequency ratio. Therefore, MTLCD is proposed to protect such the shortcoming of STLCD. The result of numerical analysis presents improved performance for robustness of MTLCD

  • PDF

An Experimental Study on Motions of two Pin-jointed Multi-floating Bodies (Pin-joint 연결된 다수 부유체의 운동에 대한 실험적 연구)

  • Lee, Seung-Chul;Bae, Sung-Yong;Goo, Ja-Sam
    • Journal of Power System Engineering
    • /
    • v.20 no.3
    • /
    • pp.5-10
    • /
    • 2016
  • The structure of the variable liquid column oscillator(VLCO) is analogous to that of the tuned liquid column damper used to suppress oscillatory motion in large structures like tall buildings and cargo ships. VLCO is using the technology which absorbs high potential energy made by process of accelerated motions effect of air spring by installation of inner air chamber. So, the application of VLCO can improve the efficiency of energy than that of wave energy converters made in Pelamis Company. In this research, experiments were performed for the models which have two different liquid column sizes. In order to find out the biggest motion response, two major conditions are taken into account. Two conditions are to open(or close) the valves and to differentiate the height of the liquid column.

A study on Motion Characteristics of VLCO by Draft (Simple floating body) (가변진동수주장치의 흘수변화에 따른 운동특성연구 (단일 부유체))

  • Lee, Seung-Chul;Bae, Sung-Yong
    • Journal of Power System Engineering
    • /
    • v.18 no.5
    • /
    • pp.16-21
    • /
    • 2014
  • The structure of the variable liquid column oscillator(VLCO) is analogous to that of the tuned liquide column damper used to suppress oscillatory motion in large structures like tall buildings and cargo ships. VLCO is the technology to absorb high potential energy made by process of accelerated motions to occur the effect of an air spring by installation of inner air chamber. So, the application of VLCO can obtain to improve efficiency of energy than wave energy converters made in Pelamis Company. In this research, the experiments were carried out for the motion characteristics of simple floating body by varying the amount of internal fluid. The experimental results were compared with the calculated results.

Design tables and charts for uniform and non-uniform tuned liquid column dampers in harmonic pitching motion

  • Wu, Jong-Cheng;Wang, Yen-Po;Chen, Yi-Hsuan
    • Smart Structures and Systems
    • /
    • v.9 no.2
    • /
    • pp.165-188
    • /
    • 2012
  • In the first part of the paper, the optimal design parameters for tuned liquid column dampers (TLCD) in harmonic pitching motion were investigated. The configurations in design tables include uniform and non-uniform TLCDs with cross-sectional ratios of 0.3, 0.6, 1, 2 and 3 for the design in different situations. A closed-form solution of the structural response was used for performing numerical optimization. The results from optimization indicate that the optimal structural response always occurs when the two resonant peaks along the frequency axis are equal. The optimal frequency tuning ratio, optimal head loss coefficient, the corresponding response and other useful quantities are constructed in design tables as a guideline for practitioners. As the value of the head loss coefficient is only available through experiments, in the second part of the paper, the prediction of head loss coefficients in the form of a design chart are proposed based on a series of large scale tests in pitching base motions, aiming to ease the predicament of lacking the information of head loss for those who wishes to make designs without going through experimentation. A large extent of TLCDs with cross-sectional ratios of 0.3, 0.6, 1, 2 and 3 and orifice blocking ratios ranging from 0%, 20%, 40%, 60% to 80% were inspected by means of a closed-form solution under harmonic base motion for identification. For the convenience of practical use, the corresponding empirical formulas for predicting head loss coefficients of TLCDs in relation to the cross-sectional ratio and the orifice blocking ratio were also proposed. For supplemental information to horizontal base motion, the relation of head loss values versus blocking ratios and the corresponding empirical formulas were also presented in the end.

Dynamic Characteristics of Tuned Liquid Column Dampers Using Shaking Table Test (진동대실험에 의한 동조액체기둥감쇠기의 동적특성)

  • Min, Kyung-Won;Park, Eun-Churn
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.19 no.6
    • /
    • pp.620-627
    • /
    • 2009
  • Shaking table test was carried out to obtain dynamic characteristics of TLCDs with uniform and non-uniform sections for both horizontal and vertical tubes. The input to the table is harmonic acceleration with constant magnitude. The output is horizontal dynamic force which is measured by load cell installed below the TLCD. Transfer functions are experimentally obtained using the ratio of input and output. Natural frequency, the most important design factor, is compared to that by theoretical equation for TLCDs with five different water levels. System identification process is performed for experimentally obtained transfer functions to find the dynamic characteristics of head loss coefficient and effective mass of TLCDs. It is found that their magnitudes are larger for a TLCD with non-uniform section than with uniform section and natural frequencies are close to theoretical ones.

Experimental study on motions of VLCO for wave power generation (2. Multiple floating bodies) (파력발전용 가변수주진동장치의 운동에 대한 실험적 연구 (2. 다수 부유체))

  • Lee, Seung-Chul;Goo, Ja-Sam
    • Journal of Ocean Engineering and Technology
    • /
    • v.27 no.6
    • /
    • pp.27-31
    • /
    • 2013
  • The structure of a variable liquid column oscillator(VLCO) is analogous to that of the tuned liquid column damper used to suppress oscillatory motion in large structures like tall buildings and cargo ships. The VLCO is a system for absorbing the high kinetic energy of the accelerated motions of multiple floating bodies using an air-spring effect produced the installation of inner air chambers. Thus, a VLCO can improve the energy efficiency of the activating object type of wave energy converters made by the Pelamis Company. In this research, an experiment was performed in two cases: with the top valves closed and open. The floating bodies were connected by hinges. The effect of the internal flow was estimated by comparing the results for the closed and open valves.

Development of a methodology for damping of tall buildings motion using TLCD devices

  • Diana, Giorgio;Resta, Ferruccio;Sabato, Diego;Tomasini, Gisella
    • Wind and Structures
    • /
    • v.17 no.6
    • /
    • pp.629-646
    • /
    • 2013
  • One of the most common solutions adopted to reduce vibrations of skyscrapers due to wind or earthquake action is to add external damping devices to these structures, such as a TMD (Tuned Mass Damper) or TLCD (Tuned Liquid Column Damper). It is well known that a TLCD device introduces on the structure a nonlinear damping force whose effect decreases when the amplitude of its motion increases. The main objective of this paper is to describe a Hardware-in-the-Loop test able to validate the effectiveness of the TLCD by simulating the real behavior of a tower subjected to the combined action of wind and a TLCD, considering also the nonlinear effects associated with the damping device behavior. Within this test procedure a scaled TLCD physical model represents the hardware component while the building dynamics are reproduced using a numerical model based on a modal approach. Thanks to the Politecnico di Milano wind tunnel, wind forces acting on the building were calculated from the pressure distributions measured on a scale model. In addition, in the first part of the paper, a new method for evaluating the dissipating characteristics of a TLCD based on an energy approach is presented. This new methodology allows direct linking of the TLCD to be directly linked to the increased damping acting on the structure, facilitating the preliminary design of these devices.

Passive, semi-active, and active tuned-liquid-column dampers

  • Chen, Yung-Hsiang;Ding, Ying-Jan
    • Structural Engineering and Mechanics
    • /
    • v.30 no.1
    • /
    • pp.1-20
    • /
    • 2008
  • The dynamic characteristics of the passive, semi-active, and active tuned-liquidcolumn dampers (or TLCDs) are studied in this paper. The design of the latter two are based on the first one. A water-head difference (or simply named as water head in this paper) of a passive TLCD is pre-set to form the so-called semi-active one in this paper. The pre-set of water head is released at a proper time instant during an earthquake excitation in order to enhance the vibration reduction of a structure. Two propellers are installed along a shaft inside and at the center of a passive TLCD to form an active one. These two propellers are driven by a servo-motor controlled by a computer to provide the control force. The seismic responses of a five-story shear building with a passive, semiactive, and active TLCDs are computed for demonstration and discussion. The responses of this building with a tuned mass damper (or TMD) are also included for comparison. The small-scale shaking-table experiments of a pendulum-like system with a passive or active TLCD to harmonic and seismic excitations are conducted for verification.

Experimental study of controllable MR-TLCD applied to the mitigation of structure vibration

  • Cheng, Chih-Wen;Lee, Hsien Hua;Luo, Yuan-Tzuo
    • Smart Structures and Systems
    • /
    • v.15 no.6
    • /
    • pp.1481-1501
    • /
    • 2015
  • MR-TLCD (Magneto-Rheological Tuned Liquid Column Damper) is a new developed vibration control device, which combines the traditional passive control property with active controllability advantage. Based on traditional TLCD governing equation, this study further considers MR-fluid viscosity in the equation and by transforming the non-linear damping term into an equivalent linear damping, a solution can be obtained. In order to find a countable set of parameters for the design of the MR-TLCD system and also to realize its applicability to structures, a series of experimental test were designed and carried out. The testing programs include the basic material properties of the MR-fluid, the damping ratio of a MR-TLCD and the dynamic responses for a frame structure equipped with the MR-TLCD system subjected to strong ground excitations. In both the analytical and experimental results of this study, it is found that the accurately tuned MR-TLCD system could effectively reduce the dynamic response of a structural system.