• Title/Summary/Keyword: liquid sloshing

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Shaking Table Test of Rectangular Liquid Container with Base-Isolation System (사각형 면진유체저장조의 진동대실험)

  • 전영선;최인길
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.04a
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    • pp.122-129
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    • 1995
  • The seismic behavior of a rectangular liquid container with high damping laminated rubber bearing is investigated through the scaled model tests. The results are compared with those for non-isolated model, and those by analytical methods. It is shown that the optimum dynamic properties of isolation system can reduce the acceleration response in the superstructure significantly and prevent the amplification of sloshing height.

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Review of Propellant Vibration and Control of Liquid Rocket Fuselage Feeding System (액체로켓 기체공급계의 추진제 진동특성 및 제어기술 동향)

  • Cho, Nam-Kyung;Kho, Hyun-Seok;Han, Sang-Yeop;Cho, In-Hyun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.05a
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    • pp.89-94
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    • 2010
  • Fuselage propellant feeding system should supply propellants to engine with required flow rate, temperature and pressure. Propellant vibration in engine and feeding line changes feeding characteristics, and frequently inhibits to satisfy the required feeding requirements. Sloshing and POGO vibration are known to be the major vibration phenomena. Concerning sloshing and POGO, vehicle control and structural dynamics aspects are extensively studied, whereas, its effect on propellant feeding performance is not clearly understood. This paper focuses on the deviation of required feeding performance due to propellant vibration. Overall characteristics of propellant vibration and its effect on propellant supply to engine are reviewed and control mechanism for suppressing vibration is introduced.

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Three Dimesional Analysis of Liquid Storage Tanks Using FE-BE Coupling Method in Frequency Domin (유한요소-경계요소 조합에 의한 3차원 유체저장 구조물의 주파수 응답해석)

  • 김문겸
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.04a
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    • pp.275-283
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    • 1999
  • To predict the dynamic behavior of the cylindrical liquid storage tank subjected to seismic ground motion three dimesional analysis with liquid-structure interaction must be performed, In this study a three dimensional dynamic analysis method over the frequency domain using FE-BE coupling technique which combines the efficiency of the boundary elements for liquid with the versatility of the finite shell elements for tank. The liquid region is modeled using boundary elements which can counter the sloshing effect at free surface and the structure region the tank itself is modeled using the degenerated finite shell elements. At the beginning of the procedure the equivalent mass matrix of the liquid is generated by boundary elements procedure. Then this equivalent mass matrix is combined with the mass matrix of the structure to produce the global mass matrix in the equation of the motion of fluid-structure interaction problem In order to demonstrate the accuracy and validity of the developed method the numerical results re compared with the previous studies. Finally the effects of the fluid-structure interaction on the natural frequency and dynamic response of the system are analyzed.

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Influence of torsional rigidity of flexible appendages on the dynamics of spacecrafts

  • Chiba, Masakatsu;Magata, Hidetake
    • Coupled systems mechanics
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    • v.8 no.1
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    • pp.19-38
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    • 2019
  • The influence of torsional rigidity of hinged flexible appendage on the linear dynamics of flexible spacecrafts with liquid on board was analyzed by considering the spacecraft's main body as a rigid tank, its flexible appendages as two elastically supported elastic beams, and the onboard liquid as an ideal liquid. The meniscus of the liquid free surface due to surface tension was considered. Using the Lagrangian of the spacecraft's main body (rigid tank), onboard liquid, and two beams (flexible appendages) in addition to assuming the system moved symmetrically, the coupled system frequency equations were obtained by applying the Rayleigh-Ritz method. The influence of the torsional rigidity of the flexible appendages on the spacecraft's coupled vibration characteristics was primary focus of investigation. It was found that coupled vibration modes especially that of appendage considerably changed with torsion spring parameter ${\kappa}_t$ of the flexible appendage. In addition, variation of the main body displacement with system parameters was investigated.

Resonant Frequencies in Rectangular Liquid Tanks with an Internal Body (내부물체를 갖는 사각형수조내 유체의 고유진동수)

  • 전영선;윤정방
    • Computational Structural Engineering
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    • v.9 no.1
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    • pp.55-64
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    • 1996
  • Sloshing frequencies of the fluid in rectangular tanks with a bottom-mounted rectangular block are determined by linear water wave theory. Velocity potential is decomposed into those for the wall-induced waves, and the reflected, transmitted, and scattered waves by the block. The reflection and transmission coefficients are determined using the continuity conditions of mass flux and energy flux on the common vertical boundaries of the fluid regions, and the boundary conditions on the both sides of the block. The analysis results indicate that the sloshing frequencies reduce, as the block becomes tall and vade and as the block moves toward the center. The variations of the sloshing frequencies due to the block are found to be more sensitive in broad thanks than is tall tanks.

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Sloshing Damping in a Swaying Rectangular Tank Using a Porous Bulkhead (투과성 격벽을 이용한 수평 운동하는 사각형 탱크내의 슬로싱 감쇠)

  • Cho, Il-Hyoung
    • Journal of Ocean Engineering and Technology
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    • v.32 no.4
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    • pp.228-236
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    • 2018
  • The performance of a porous swash bulkhead for the reduction of the resonant liquid motion in a swaying rectangular tank was investigated based on the assumption of linear potential theory. The Galerkin method (Porter and Evans, 1995) was used to solve the potential flow model by adding a viscous frictional damping term to the free-surface condition. By comparing the experimental results and the analytical solutions, we verified that the frictional damping coefficient was 0.4. Darcy's law was used to consider the energy dissipation at a porous bulkhead. The tool that was developed with a built-in frictional damping coefficient of 0.4 was confirmed by small-scale experiments. Using this tool, the free-surface elevation, hydrodynamic force (added mass, damping coefficient) on a wall, and the horizontal load on a bulkhead were assessed for various combinations of porosity and submergence depth. It was found that the vertical porous bulkhead can suppress sloshing motions significantly when properly designed and by selecting the appropriate porosity(${\approx}0.1$) and submergence depth.

Concept Design of a Parallel-type Tuned Mass Damper - Tuned Sloshing Damper System for Building Motion Control in Wind

  • Lee, Chien-Shen;Love, J. Shayne;Haskett, Trevor C.;Robinson, Jamieson K.
    • International Journal of High-Rise Buildings
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    • v.10 no.2
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    • pp.93-97
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    • 2021
  • Supplementary damping systems, such as tuned mass dampers (TMDs) and tuned sloshing dampers (TSDs) - also known as tuned liquid dampers (TLDs) - have been successfully employed to reduce building motion during wind events. A design of a damping system consisting of a TMD and two TSDs performing in unison has been developed for a tall building in Taiwan to reduce wind-induced motion. The architecturally exposed TMD will also be featured as a tourist attraction. The dual-purpose TSD tanks will perform as fire suppression water storage tanks. Linearized equivalent mechanical TSD and TMD models are coupled to the structure to simulate the multi-degree of freedom system response. Frequency response curves for the structure with and without the damping system are created to evaluate the performance of the damping system. The performance of the combined TMD-TSD system is evaluated against a conventional TMD system by computing the effective damping produced by each system. The proposed system is found to have superior performance in acceleration reduction. The combined TMD-TSD system is an effective and affordable means to reduce the wind-induced resonant response of tall buildings.

A Study on Generation Method of Sloshing Impact Pressure Data Using Generative Adversarial Networks (GAN을 이용한 슬로싱 충격압력 데이터 생성 방법 연구)

  • Bo-gyeong Kang;Sang-jin Oh;Sang-Beom Lee;Jun-Hyung Jung;Sung-chul Shin
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.1
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    • pp.35-46
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    • 2023
  • A model test is performed to measure the sloshing impact pressure in the liquid tank. A preprocessing is performed to learn the model test results applied with various environmental conditions. In this study, we propose a method for generating data similar to the total pressure data using Generative Adversarial Networks. In addition, after approximating the generated result to the three parameter Weibull distribution, the difference of the three parameters was compared through the RMSE and SMAPE calculation results. As a result, the distribution of the generated data showed similar results to the total pressure data distribution.

Coupled hydroelastic vibrations of a liquid on flexible space structures under zero-gravity - Part I. Mechanical model

  • Chiba, Masakatsu;Chiba, Shinya;Takemura, Kousuke
    • Coupled systems mechanics
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    • v.2 no.4
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    • pp.303-327
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    • 2013
  • The coupled free vibration of flexible structures and on-board liquid in zero gravity space was analyzed, considering the spacecraft main body as a rigid mass, the flexible appendages as two elastic beams, and the on-board liquid as a "spring-mass" system. Using the Lagrangians of a rigid mass (spacecraft main body), "spring-mass" (liquid), and two beams (flexible appendages), as well as assuming symmetric motion of the system, we obtained the frequency equations of the coupled system by applying Rayleigh-Ritz method. Solving these frequency equations, which are governed by three system parameters, as an eigenvalue problem, we obtained the coupled natural frequencies and vibration modes. We define the parameter for evaluating the magnitudes of coupled motions of the added mass (liquid) and beam (appendages). It was found that when varying one system parameter, the frequency curves veer, vibration modes exchange, and the significant coupling occurs not in the region closest to the two frequency curves but in the two regions separate from that region.