• 제목/요약/키워드: Control of outflow discharge

검색결과 20건 처리시간 0.027초

유량조절이 가능한 사이펀 여수로 수리모형실험 (Hydrualic Model Test for Siphon Spillway Capable of Controlling Discharge)

  • 정재상;장은철;이창훈
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2019년도 학술발표회
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    • pp.43-47
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    • 2019
  • 본 연구에서는 수리모형실험을 통해 사이펀 여수로에 장착된 air slot의 방류량 조절 능력을 검토하였다. air slot의 단면 형상으로 원호 및 직사각형 형상을 채택하였으며, 개구부 면적을 조절할 수 있게 하였다. air slot이 장착된 경우 사이펀 관 내부에 공기와 물이 혼합된 복잡한 흐름이 발생하였다. air slot이 장착된 사이펀 여수로에서 저수지 내측 수위가 상승할 때와 하강할 때 동일한 수위에서 동일한 유량이 계측되었다. air slot의 무차원 개구부 면적이 증가할수록 무차원 방류량은 더 서서히 증가하였다. 수리모형실험 결과는 air slot의 면적 조절을 통해 사이펀을 통한 방류량 조절이 가능함을 보여주었다.

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사이펀 여수로 공기혼입장치(air slot)의 방류량 조절 능력에 대한 실험 연구 (Experimental Study for Capability of Air Slot in Siphon Spillway to Control Outflow Discharge)

  • 정재상;장은철;이창훈
    • 대한토목학회논문집
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    • 제39권6호
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    • pp.703-712
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    • 2019
  • 본 연구에서는 수리모형실험을 통해 사이펀 여수로에 장착된 공기혼입장치(air slot)의 방류량 조절 능력을 검토하였다. 공기혼입장치의 단면 형상으로 원호 및 직사각형 형상을 채택하였으며, 개구부 면적을 조절할 수 있게 하였다. 공기혼입장치가 장착된 경우 사이펀 관 내부에 공기와 물이 혼합된 복잡한 흐름이 발생하였다. 공기혼입장치가 장착된 사이펀 여수로에서 저수지 내측 수위가 상승할 때와 하강할 때 동일한 수위에서 동일한 유량이 계측되었다. 공기혼입장치의 무차원 개구부 면적이 증가할수록 일정한 수두차 및 저수지 수위 조건에서 무차원 방류량은 감소하였다. 수리모형실험 결과는 공기혼입장치의 면적 조절을 통해 사이펀을 통한 방류량 조절이 가능함을 보여주었다.

전산유동해석을 이용한 ORIFICE 방출 계수 예측 (PREDICTION OF THE ORIFICE DISCHARGE COEFFICIENT USING COMPUTATIONAL FLUIDS DYNAMICS)

  • 옥호남;김인선
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2006년도 추계 학술대회논문집
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    • pp.147-150
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    • 2006
  • Vent ports are installed on the walls of closed compartments of a launch vehicle to control the pressure drop in the compartments. The ports can be modelled as an orifice, and the accurate prediction of the discharge coefficient of an orifice is essential for the design of vent ports. Experimental methods have been used to determine the discharge coefficients for various shapes of orifices, and extensive databases are available. Wind tunnel tests have been also done to evaluate the effect of interaction between venting outflow and freestream for limited conditions. The goal of the present research is to predict the discharge coefficient of an orifice using CFD and evaluate the accuracy of the method, especially for the orifices exposed to the external flow.

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경사지 밭에서 발생하는 토양유실 저감을 위한 피복재 적용 (Surface Cover Application for Reduction of Runoff and Sediment Discharge from Sloping Fields)

  • 신민환;원철희;박운지;최용훈;신재영;임경재;최중대
    • 한국농공학회논문집
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    • 제53권6호
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    • pp.129-136
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    • 2011
  • To measure effects of surface cover on runoff and sediment discharge reduction using rainfall simulator, four(5 m${\times}$30 m scale) plot experiments were conducted in this study. Surface covers made with straw mat, Polyacrylamide (PAM), chaff, and sawdust were simulated 4 times under 31.1~44.4 mm/hr rainfall intensities. Compared with results from control plot, the time of runoff generation is delayed and outflow volume decreased with surface cover. Effects on runoff reduction of straw mat, PAM, sawdust and chaff ranged 4.7~81.5 % and runoff rate reduced by 6.5~76.1 % respectively, when compared with those from control plot. The percentage of decrease in sediment discharge were 99.7~99.8 % from straw mat+sawdust+PAM plots, 85.9~95.6 % from straw mat+PAM plots, and 98.5~99.4 % from straw mat+chaff+PAM plots. The runoff, sediment discharge, and SS concentration reduction efficiencies of the cover materials were outstanding when compared to control plot. It was analyzed that reduction of runoff and sediment discharge were mainly contributed by decrease in rainfall energy impact and flow velocity and increase of infiltration due to the surface cover materials. The results could be used as a base for the development of best management practices (BMPs) to reduce runoff, sediment discharge from sloping field.

SSP 기후변화 시나리오에 따른 농업용 저수지 홍수조절능력 분석 (Analysis of Flood Control Capacity of Agricultural Reservoir Based on SSP Climate Change Scenario)

  • 김지혜;곽지혜;황순호;전상민;이성학;이재남;강문성
    • 한국농공학회논문집
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    • 제63권5호
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    • pp.49-62
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    • 2021
  • The objective of this study was to evaluate the flood control capacity of the agricultural reservoir based on state-of-the-art climate change scenario - SSP (Shared Socioeconomic Pathways). 18 agricultural reservoirs were selected as the study sites, and future rainfall data based on SSP scenario provided by CMIP6 (Coupled Model Intercomparison Project 6) was applied to analyze the impact of climate change. The frequency analysis module, the rainfall-runoff module, the reservoir operation module, and their linkage system were built and applied to simulate probable rainfall, maximum inflow, maximum outflow, and maximum water level of the reservoirs. And the maximum values were compared with the design values, such as design flood of reservoirs, design flood of direct downstream, and top of dam elevation, respectively. According to whether or not the maximum values exceed each design value, cases were divided into eight categories; I-O-H, I-O, I-H, I, O-H, O, H, X. Probable rainfall (200-yr frequency, 12-h duration) for observed data (1973~2020) was a maximum of 445.2 mm and increased to 619.1~1,359.7 mm in the future (2011~2100). For the present, 61.1% of the reservoirs corresponded to I-O, which means the reservoirs have sufficient capacity to discharge large inflow; however, there is a risk of overflowing downstream due to excessive outflow. For the future, six reservoirs (Idong, Baekgok, Yedang, Tapjung, Naju, Jangsung) were changed from I-O to I-O-H, which means inflow increases beyond the discharge capacity due to climate change, and there is a risk of collapse due to dam overflow.

홍수기 저수지의 최적연계운영 (The optimal operation of reservoir systems during flood season)

  • 한건연;최현구;김동일;이경택
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.743-746
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    • 2008
  • Recently, due to the effect of global warming and extreme rainfall, the magnitude of flood disaster and the frequency of flood is rapidly increasing. In order to mitigate the damage of human and property from this kind of meteorological phenomenon and manage water resources scientifically, effective operation of dam and reservoir is very important. In case of Andong dam which was not performed a flood control function needs to develop new types of dam safety management measure because of recent extraordinary flood by typhoons. In case of Andong dam and Imha dam, I am using HEC-5 model in order to apply reservoir simulation. In this case, complex conditions among 100-year floods , 200-year floods and PMF was used. Also, I modified the maximum outflow 3,800m3/s into 3,490m3/s and applied this modified discharge in order to secure freeboard in the downstream. In an analysis that I applied modified outflow by 100-year floods and 200-year floods to, the result showed that river didn't overflow in Andong area but some other places have relatively low freeboard. In the cases that I modified maximum outflow, results showed that freeboard of levee is larger than existed simulation. In the simulation that I applied 200-year floods and PMF to and under a condition connected with PMF, results showed overflowing the levees. Because of the difference between the frequency of dam outflow and the design flood in river, it is required to improve the existed flood plan in the downstream of Andong dam. As a result of this study, the optimal operation of reservoir systems can be proposed to mitigate the flood damage in the downstream of Andong dam and also can be used to establish the flood plans.

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정압비례제어방식을 적용한 정압급수장치의 개발 (Development of a constant pressure feed system using a constant pressure proportional control mode)

  • 김주명;김광열;이건기
    • 한국정보통신학회논문지
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    • 제7권5호
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    • pp.1026-1031
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    • 2003
  • 자동 급수펌프는 압력스위치에 의해 운전 및 정지를 하게 된다. 따라서 수량 증감에 따른 펌프의 빈번한 운전 및 정지로 인해 지속적인 정격 및 정압 운전이 불가능하다. 또한 빈번한 작동으로 인해 지속적으로 일정한 압력을 얻을 수 없으며, 펌프의 소손과 에너지의 낭비가 심한 단점을 가지고 있다. 본 논문에서는 이러한 단점을 해결하고자 급수밸브, 유량센서, 제어장치로 구성되는 정압 급수장치를 설계 제작하였다. 급수밸브는 유출되는 물의 양과 관계없이 항상 일정한 양의 물을 유입하여 펌프의 부하를 줄이는 역할을 한다. 유량센서는 적외선 다이오드를 사용하여 유출되는 물의 양의 측정하며, 제어장치는 8 비트 마이크로프로세서를 이용하여 설계하였으며, 특별한 제어 알고리듬에 의해 펌프의 운전과 정지를 제어하게 하였다. 본 논문에서 개발한 장치는 토출 압력이 일정하게 유지되고 펌프의 작동 및 정지 동작이 부드럽게 이루어지며, 펌프의 지속적인 정압운전이 가능하므로 기존의 단점을 보완하는 장치로 사료된다.

탁수조절을 위한 소양호 선택취수설비 설치 효과 분석 (Effect of Installing a Selective Withdrawal Structure for the Control of Turbid Water in Soyang Reservoir)

  • 정세웅;박형석;윤성완;류인구
    • 한국물환경학회지
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    • 제27권6호
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    • pp.743-753
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    • 2011
  • One of the most important water management issues of Soyang Reservoir, located in North Han River in Korea, is a long term discharge of turbid water to downstream during flood season. Installation of a selective withdrawal structure (SWS) is planned by the reservoir management institute as a control measure of outflow water quality and associated negative impacts on downstream water use and ecosystem. The objective of the study was to explore the effectiveness of the SWS on the control of outflow turbidity under two different hydrological years; one for normal flood year and another for extreme flood year. A two-dimensional (2D), laterally averaged hydrodynamic and water quality model (CE-QUAL-W2) was set up and calibrated for the reservoir and used to evaluate the performance of the proposed SWS. The results revealed that the SWS can be an effective method when the ${\Theta}$ value, the ratio between the amount of turbid water that containing suspended sediment (SS) greater than 25 mg/L and the total storage of the reservoir, is 0.59 during the normal flood year. However, the effectiveness of the SWS could be marginal or negative in the extreme flood year when ${\Theta}$ was 0.83. The results imply that the SWS is an effective alternative for the control of turbid water for moderate flood events, but not a sufficient measure for large flood events that are expected to happen more often in the future because of climate change.

주암조절지댐 방류수에 따른 하천 및 순천만 일대 수온변화 조사분석 (A Investigation and Analysis of Water Temperature by Juam Regulation Dam Outflow in Downstream and Suncheon Bay)

  • 이현노;정관수;천근호;허영택
    • 한국수자원학회논문집
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    • 제48권6호
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    • pp.501-509
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    • 2015
  • 최근의 다목적댐 운영은 기존의 홍수조절, 용수공급, 수력발전과 같은 수량뿐만이 아니라 수질, 생태환경 등 다양한 이해관계를 고려하도록 요구받고 있다. 본 연구의 목적은 주암조절지댐의 저온 심층수 방류로 인해 사회적 갈등이 있는 지역을 대상으로 수온을 조사하고, 수온변화 특성을 분석하는 것이다. 본 연구에서는 주암조절지댐, 하류하천, 순천만 지역에 대해 장기간에 걸쳐 수온을 모니터링 하였으며, 3차원 수치모형(EFDC)을 활용하여 방류량과 같은 다양한 외부 인자들을 고려하여 하류하천 및 순천만에서의 수온변화를 비교 분석하였다. 모니터링 및 수치모의 결과 댐의 저온 방류수 영향은 대체적으로 4월~9월 기간에 나타나는 것을 알 수 있었으며, 또한 댐 저온수 방류 영향이 방류시기, 방류수온, 방류량, 기상, 조위 등 다양한 인자에 의해 복잡한 형태로 변화한 것을 알 수 있었다. 본 연구의 결과는 댐의 저온수 방류로 인한 하류하천 및 연안지역 악영향을 최소화하기 위한 댐 운영 개선방안 수립시 기초자료로 활용될 수 있을 것으로 판단된다.

댐 배수조작에 따른 저수지내 탁수변화 모의 - 대청댐을 대상으로 - (Simulation of Turbid Water in the Stratified Daecheong Reservoir during Gate Operation)

  • 이재일;서세덕;이규성;하성룡
    • 환경영향평가
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    • 제18권6호
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    • pp.377-386
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    • 2009
  • Due to severe flooding, the long-term residence of turbidity flows within the stratified Daecheong Reservoir have lengthened. A long-term residence of turbidity flows within the stratified Daecheong Reservoir after floods has been major environmental issue. The objective of this study was to assess the impact to water supply from the hydrodynamics and turbidity outflow. Two gate operation scenarios were investigated. Scenario A refers to gate operations according to rainfall events, and scenario B refers to gate operations according to inflow. From the results of secenario A, the SS concentrations decreased from 0.44mg/l to 0.54mg/l at the front of the dam, whereas SS concentrations increased from 0.24mg/l to 1.24mg/l at the intake points at Munhi and Daejeon. From the results of scenario B, the SS concentrations decreased from 0.61mg/l to 0.83mg/l at the front of Dam; howeve, SS concentrations also decreased from 0.16mg/l to 0.48mg/l at the intake points at Munhi and Daejeon. It seems that it may be more efficient to control turbidity by creating additional outflows of generated discharge after intensive rainfalls than not.