• Title/Summary/Keyword: Liquid column

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Characteristics of Gas-liquid Mass Transfer and Interfacial Area in a Bubble Column

  • Lim, Dae Ho;Yoo, Dong Jun;Kang, Yong
    • Korean Chemical Engineering Research
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    • v.53 no.3
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    • pp.315-320
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    • 2015
  • Characteristics of gas-liquid mass transfer and interfacial area were investigated in a bubble column of diameter and height of 0.102 m and 2.5 m, respectively. Effects of gas and liquid velocities on the volumetric gas-liquid mass transfer coefficient ($k_La$), interfacial area (a) and liquid side true mass transfer coefficient ($k_L$) were examined. The interfacial area and volumetric gas-liquid mass transfer coefficient were determined directly by adopting the simultaneous physical desorption of $O_2$ and chemical absorption of $CO_2$ in the column. The values of $k_La$ and a increased with increasing gas velocity but decreased with increasing liquid velocity in the bubble column which was operated in the churn turbulent flow regime. The value of $k_L$ increased with increasing gas velocity but did not change considerably with increasing liquid velocity. The liquid side mass transfer was found to be related closely to the liquid circulation as well as the effective contacting frequency between the bubbles and liquid phases.

Bi-directional response control of a building using one TLD (1 개의 TLD 를 이용한 건물의 양방향 진동제어)

  • Min, Kyung-Won;Lee, Sung-Kyung;Park, Eun-Churn
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2009.04a
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    • pp.119-124
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    • 2009
  • This paper proposes a tuned liquid column sloshing damper(TLCSD) and presents experimental results to evaluate its control performance. The proposed damper acts as a tuned liquid column damper(TLCD) and a tuned liquid damper(TLD), respectively, in both principal axes of building structures. Shaking table test was performed to grasp its dynamic characteristics. Testing results showed that under inclined incident excitations, a TLCSD used in this study have dynamic characteristics coupled by both TLCD and TLD.

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An effect of initial disturbance on the breakup mechanism of liquid jet (초기교란이 액주의 분열기구에 미치는 영향)

  • Seok, J.K.;Park, Y.K.;Lee, C.W.
    • Journal of ILASS-Korea
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    • v.3 no.2
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    • pp.34-41
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    • 1998
  • The present experimental study investigates the effect of an initial disturbance on the breakup mechanism of a liquid column. With varying the maginitude of the inital disturbance, we measure the surface wave of liquid column with adopting laser shadow method and analyze the growth rate of liquid column and breakup frequency. The experimental results show that thebreakup characteristics of liquid column is significantly influenced by the frequency of the initial disturbance. We concluded that the most uniform droplet occurs when the frequency of initial disturbance coincides with the natural frequency of the liquid column.

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Empirical Correlations for Breakup Length of Liquid Jet in Uniform Cross Flow-A Review

  • No, Soo-Young
    • Journal of ILASS-Korea
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    • v.18 no.1
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    • pp.35-43
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    • 2013
  • The empirical correlations for the prediction of breakup length of liquid jet in uniform cross flow are reviewed and classified in this study. The breakup length of liquid jets in cross flow was normally discussed in terms of the distances from the nozzle exit to the column breakup location in the x and y directions, called as column fracture distance and column fracture height, respectively. The empirical correlations for the prediction of column fracture distance can be classified as constant form, momentum flux ratio form, Weber number form and other parameter form, respectively. In addition, the empirical correlations for the prediction of column fracture height can be grouped as momentum flux ratio form, Weber number form and other parameter form, respectively. It can be summarized that the breakup length of liquid jet in a cross flow is a basically function of the liquid to air momentum flux ratio. However, Weber number, liquid-to-air viscosity ratio and density ratio, Reynolds number or Ohnesorge number were incorporated in the empirical correlations depending on the investigators. It is clear that there exist the remarkable discrepancies of predicted values by the existing correlations even though many correlations have the same functional form. The possible reasons for discrepancies can be summarized as the different experimental conditions including jet operating condition and nozzle geometry, measurement and image processing techniques introduced in the experiment, difficulties in defining the breakup location etc. The evaluation of the existing empirical correlations for the prediction of breakup length of liquid jet in a uniform cross flow is required.

Numerical Analysis for Breakup of Liquid Jet in Crossflow (기체 유동에 수직 분사된 액체의 분해에 대한 수치적 해석)

  • Park, Sun-Il;Chang, Keun-Shik;Moon, Yun-Wan;Sah, Jong-Youb
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1629-1633
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    • 2004
  • Liquid is commonly introduced as transversal jets in venturi scrubber which is one of the gas cleaning equipments. The jet dynamics such as penetration and breakup is of fundamental importance to the dust-collection efficiency. We have developed a model that can numerically simulate the breakup of the liquid jet in crossflow. This simulation consists of models on liquid column, jet surface breakup, column fracture and secondary droplet breakup. These models have been embedded in the KIVA3-V code. We have calculated such parameters as the jet penetration, jet trajectory, droplet size, velocity field and the volume flux distribution. The results are compared with the experimental data in this paper.

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Studies on Variable Liquid-Column Oscillator for High Efficiency Floating Wave Energy Conversion System (가변 수주진동장치를 이용한 고효율 파력발전에 관한 연구)

  • Yang, Dong-Soon;Cho, Byung-Hak
    • Journal of Ocean Engineering and Technology
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    • v.23 no.5
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    • pp.15-24
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    • 2009
  • The results of a simulation study of variable liquid column oscillations in U-tanks with a novel control scheme are presented. The configuration under investigation is analogous to that of the tuned liquid-column damper used to suppress oscillatory motion in large structures like tall buildings and cargo ships. However, by virtue of an adequate controller, the response of amplitude of the U-tanks becomes larger in a desired frequency range. The motion of wave energy conversion system equipped with a variable liquid column oscillator is described by a series of nonlinear differential equations. The equations describe the motion of body under ocean wave excitation, and the motion of liquid with an air-spring effect caused by the compression and expansion of air in vertical liquid columns and air chambers. It is shown that the effect of the air-spring has a vital role to maintain the natural frequency of oscillation in the system to synchronize with the frequency of the ocean wave, thus the system provides the most effective mode for energy extraction from the ocean.

Tuned liquid column dampers with adaptive tuning capacity for structural vibration control

  • Shum, K.M.;Xu, Y.L.
    • Structural Engineering and Mechanics
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    • v.20 no.5
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    • pp.543-558
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    • 2005
  • The natural frequencies of a long span bridge vary during its construction and it is thus difficult to apply traditional tuned liquid column dampers (TLCD) with a fixed configuration to reduce bridge vibration. The restriction of TLCD imposed by frequency tuning requirement also make it difficult to be applied to structure with either very low or high natural frequency. A semi-active tuned liquid column damper (SATLCD), whose natural frequency can be altered by active control of liquid column pressure, is studied in this paper. The principle of SATLCD with adaptive tuning capacity is first introduced. The analytical models are then developed for lateral vibration of a structure with SATLCD and torsional vibration of a structure with SATLCD, respectively, under either harmonic or white noise excitation. The non-linear damping property of SATLCD is linearized by an equivalent linearization technique. Extensive parametric studies are finally carried out in the frequency domain to find the beneficial parameters by which the maximum vibration reduction can be achieved. The key parameters investigated include the distance from the centre line of SATLCD to the rotational axis of a structure, the ratio of horizontal length to the total length of liquid column, head loss coefficient, and frequency offset ratio. The investigations demonstrate that SATLCD can provide a greater flexibility for its application in practice and achieve a high degree of vibration reduction. The sensitivity of SATLCD to the frequency offset between the damper and structure can be improved by adapting its frequency precisely to the measured structural frequency.

Effects of Angled Injection on the Spray Characteristics of Liquid Jets in Subsonic Crossflow (아음속 수직분사제트에서 분사각도 영향에 대한 분무특성 연구)

  • Kim, Min-Ki;Song, Jin-Kwan;Lee, Jang-Su;Yoon, Young-Bin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.2
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    • pp.166-174
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    • 2009
  • The liquid column trajectory and column breakup length characteristics have been experimentally studied in angled jets injected into subsonic crossflow. Pulsed shadowgraph photography and Planar Liquid Laser Induced Fluorescence measurements were used to determine the angled effects. And the main objectives of this research are to get a empirical formula of liquid column trajectory and breakup length with below the $90^{\circ}$ degree injection angle conditions, and were compared with previous results. It was also found that the empirical formula, which reversed injection conditions of air stream. As the result, This has been shown that liquid column trajectories and column breakup length were spatially dependent on various injection angle, normalized injector exit diameter, air-stream and fuel injection velocity. Furthermore, the empirical formula of liquid column trajectories and breakup length has been some different of drag coefficient results between normal angled injection and reversed injection in subsonic crossflow.

The Vibration Performance Experiment of Tuned Liquid Damper and Tuned Liquid Column Damper

  • Kim Young-Moon;You Ki-Pyo;Cho Ji-Eun;Hong Dong-Pyo
    • Journal of Mechanical Science and Technology
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    • v.20 no.6
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    • pp.795-805
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    • 2006
  • Tuned Liquid damper and Tuned Liquid Column are kind of passive mechanical damper which relies on the sloshing of liquid in a rigid tank for suppressing structural vibrations. TLD and TLCD are attributable to several potential advantages - low costs ; easy to install in existing structures : effective even for small-amplitude vibrations. In this paper, the shaking table experiments were conducted to investigate the characteristics of water sloshing motion in TLD (rectangular, circular) and TLCD. The parameter obtained from the experiments were wave height, base shear force and energy dissipation. The shaking table experiments show that the liquid sloshing relies on amplitude of shaking table and frequency of tank. The TLCD was more effective control vibration than TLD.

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
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    • v.20 no.3
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    • pp.5-10
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    • 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.