• Title/Summary/Keyword: Hydraulic scale model

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Construction of a Hydraulic Scale Model for Representing the Field Tracer Experiment in River (하천 현장 실험 재현을 위한 수리모형 장치 제작)

  • Chun, Il Young;Kim, Ki Chul;Lee, Jung Lyul;Suh, Kyung Suk
    • Journal of Radiation Industry
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    • v.2 no.3
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    • pp.155-161
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    • 2008
  • A hydraulic scale model was constructed to investigate the characteristics of flows and pollutant transport in laboratory. The distorted hydraulic scale model by assuming Froude similarity was adopted to represent hydrodynamics and dispersion in a river system. The scale model was composed of water reservoir, slope control part, booster pump, distributing plate and main channel. A constructed scale model will be used to present the overall concentration profiles of tracer and a research will be performed to convert the measured values using a hydraulic scale model to real field scale.

Construction and Application of the Hydraulic Scale Model for the Analysis of Sediment Transport by Tsumani (지진해일에 의한 토사이동 해석을 위한 수리모형장치 제작 및 적용성 평가)

  • Youm, Min Kyo;Lee, Baek Gun;Min, Byung Il;Lee, Jung Lyul;Suh, Kyung-Suk
    • Journal of Radiation Industry
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    • v.7 no.2_3
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    • pp.201-207
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    • 2013
  • Soil liquefaction by tsunami or wave induced currents can cause serious damages to coastlines and coastal infrastructures. Although liquefaction caused by regular waves over sea beds has been extensively investigated, studies of tsunami-induced liquefaction near coastal area have been relatively rare. In this work, the hydraulic scale model has been designed and constructed to investigate the variations of wave height and sediment transport by tsunami. The distorted hydraulic scale model based on the Froude similarity was adopted to represent hydrodynamics and sediment transport in a coastal area. The scale model was composed of control box, screw axis, wave paddle and rotating coastal structure.

Experiments for the Characteristic Evaluation of Pollutant Transport in Tidal Influenced Region (조파역내 오염물 이동특성 평가 실험)

  • Park, Geon Hyeong;Kim, Ki Chul;Jung, Sung Hee;Suh, Kyung Suk
    • Journal of Radiation Industry
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    • v.4 no.4
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    • pp.391-395
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    • 2010
  • The characteristics for pollutant transport in tidal influenced area was investigated using tidal wave hydraulic scale model. Hydraulic scale model was composed of the tidal generator, attenuation area and channel. Also, wave height, current meter and conductivity meter were used with the measured instruments in hydraulic scale model. NaCl with a tracer was used to evaluate the advection phenomena under the different velocity profiles. The arrival time of the maximum concentration in the condition of the relatively fast velocity was measured about 30 seconds faster than ones in the conditions of low velocity. The measured concentrations of the tracer were shown in the detection points of the flow direction consecutively.

Surface Roughness Impact on Francis Turbine Performances and Prediction of Efficiency Step Up

  • Maruzewski, Pierre;Hasmatuchi, Vlad;Mombelli, Henri-Pascal;Burggraeve, Danny;Iosfin, Jacob;Finnegan, Peter;Avellan, Francois
    • International Journal of Fluid Machinery and Systems
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    • v.2 no.4
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    • pp.353-362
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    • 2009
  • In the process of turbine modernizations, the investigation of the influences of water passage roughness on radial flow machine performance is crucial and validates the efficiency step up between reduced scale model and prototype. This study presents the specific losses per component of a Francis turbine, which are estimated by CFD simulation. Simulations are performed for different water passage surface roughness heights, which represents the equivalent sand grain roughness height. As a result, the boundary layer logarithmic velocity profile still exists for rough walls, but moves closer to the wall. Consequently, the wall friction depends not only on roughness height but also on its shape and distribution. The specific losses are determined by CFD numerical simulations for each component of the prototype, taking into account its own specific sand grain roughness height. The model efficiency step up between reduced scale model and prototype value is finally computed by the assessment of specific losses on prototype and by evaluating specific losses for a reduced scale model with smooth walls. Furthermore, surveys of rough walls of each component were performed during the geometry recovery on the prototype and comparisons are made with experimental data from the EPFL Laboratory for Hydraulic Machines reduced scale model measurements. This study underlines that if rough walls are considered, the CFD approach estimates well the local friction loss coefficient. It is clear that by considering sand grain roughness heights in CFD simulations, its forms a significant part of the global performance estimation. The availability of the efficiency field measurements provides an unique opportunity to assess the CFD method in view of a systematic approach for turbine modernization step up evaluation. Moreover, this paper states that CFD is a very promising tool for future evaluation of turbine performance transposition from the scale model to the prototype.

Estimation of Hydraulic States Caused by Gate Expansion in Asan Bay (아산만 방조제 배수갑문 확장사업에 따른 주변해역 수리현상 변화 검토)

  • Park, Byong-Jun;Lee, Sang-Hwa
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.2
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    • pp.184-193
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    • 2008
  • The gate expansion was planed to increase discharge capacity of gate structure at sea dike in Asan Bay. So it was estimated for changing of hydraulic states in Pyeongteak Harbor Zone caused by gate expansion, using Delft3D, FLOW-3D and hydraulic physical scale model testing. In result, the influence of gate expansion was indicated to be weak.

A study on the similarity of coastal hydraulic model experiment of movable bed. (이동상 해안 수리모형 실험에 있어서의 상사율에 관한 연구)

  • Ok, Chi-Yul;Yang, Yun-Mo;Min, Byeong-Hyeong
    • Water for future
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    • v.15 no.4
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    • pp.31-37
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    • 1982
  • In this study, the method to determine the values of both bed-sand scale and time scale of movable bed hydraulic model experiments on beach degormation has been proposed and the results of the experiments reveal the verification of the similarity between the proto type and the model.

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Feasibility Test for Hydraulic Conductivity Characterization of Small Basin-Scale Aquifers Based on Geostatistical Evolution Strategy Using Naturally Imposed Hydraulic Stress (자연 수리자극을 이용한 소유역 규모 대수층 수리전도도 특성화: 지구통계 진화전략 역산해석 기법의 적용 가능성 시험)

  • Park, Eungyu
    • Journal of Soil and Groundwater Environment
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    • v.25 no.4
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    • pp.87-97
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    • 2020
  • In this study, the applicability of the geostatistical evolution strategy as an inverse analysis method of estimating hydraulic properties of small-scale basin was tested. The geostatistical evolution strategy is a type of data assimilation method that can effectively estimate aquifer hydraulic conductivity by combining a global optimization model of the evolution strategy and a local optimization model of the ensemble Kalman filtering. In the applicability test, the geometry, hydraulic boundary conditions, and the distribution of groundwater monitoring wells of Hanlim-Eup were employed. On the other hand, a synthetic hydraulic conductivity distribution was generated and used as the reference property for ease of estimation quality assessment. In the estimations, two different cases were tested where, in Case I, both groundwater levels and hydraulic conductivity measurements were assumed to be available, and only the groundwater levels were available, in Case II. In both cases, the reference and estimated hydraulic conductivity fields were found to show reasonable similarity, even though the prior information for estimation was not accurate. The ability to estimate hydraulic conductivity without accurate prior information suggests that this method can be used effectively to estimate mathematical properties in real-world cases, many of which little prior information is available for the aquifer conditions.

Modeling and Control of a Hydraulic Semiactive Vibration Absorber (유압식 반능동 진동 흡수기의 모델링과 제어)

  • 모창기
    • Journal of KSNVE
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    • v.8 no.4
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    • pp.700-705
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    • 1998
  • Recent past work has demonstrated that hydraulic semiactive vibration absorbers hold the promise of providing an ideal means of mitigating structural vibration. This paper examines a factor that must be treated when designing a hydraulic semiactive vibration absorber for application to a full scale structure; fluid compressibility. An expanded and consistent dynamic model of the flow process is first established. A simple feedback control is then tested on a single degree of freedom laboratory structure to verify the findings.

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Estimation of Gate Discharge Capacity by Physical Model Test and FLOW-3D (수리모형실험과 FLOW-3D를 이용한 배수갑문 통수능력 검토)

  • Park, Byong-Jun;Lee, Sang-Hwa
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.2
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    • pp.168-175
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    • 2008
  • In this study, we estimated the discharge capacity of Solicheon sluice gate in Gunjang national industrial complex by hydraulic physical scale model test and FLOW-3D. It was showed that the discharge capacity of gate carried by physical model test and numerical analysis was similar.