• 한국농공학회논문집
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• 제53권3호
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• pp.35-41
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• 2011

A model test is carried out to investigate the vibration of truss type lift gate in the four major rivers project. The gate model scaled with the ratio of 1 : 25 is made of acryl panel dimensioned 1.6 m in width, 0.28 m in height in the concrete test flume. Firstly natural frequencies of the model gate are measured and the results are compared with the numerical results in order to verify the model. The amplitudes of the vibration are measured under the different gate opening and water level conditions. The results are analyzed to study the characteristics of the gate vibration according to the small gate opening, the large gate opening and the overflow conditions. These test results presents a basic data for the guide manuals of gate management and a design method to reduce the gate vibration of truss type lift gate. Finally, the vibration of truss type lift gate are assessed in comparison with those of formerly tainter gate.

• 한국안전학회지
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• 제32권2호
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• pp.85-91
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• 2017

When the shell-type roller gate is partly open, at a certain height the large vibration is caused due to resonance and the vibration can cause damage to the gate. In this study, the review on amplitude of vibration and the possible resonance occurring at the time of opening or closing of gate is performed. Throughout the natural frequency analysis, the installation location of the measuring instrument was selected. On opening or closing of gate, the measurement of gate vibration is performed. The natural frequencies according to the opening range of the gate is analyzed. As a result of measurement and analysis, we proposed ranges in which vibration occurs largely and resonance is predicted as an avoiding open ranges, or the safe opening or closing of the shell-type roller gate. The application of this paper's avoiding open range estimation method of shell-type roller gate can be utilized as the basic data for the systematic and rational maintenance management of dams and submerged weirs in the future, and it is expected that this study can bring forth.

• 한국수자원학회논문집
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• 제37권8호
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• pp.675-685
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• 2004

본 연구에서는 FLOW-3D를 이용하여, 테인터수문이 설치된 표준 월류형 여수로에서 수문을 부분 개방했을 경우에 대한 월류흐름 거동을 해석하였다. 모의결과, 유량계수는 약 0.685에서 0.723의 범위를 가지는 것으로 분석되었다. 수문을 완전 개방한 경우의 월류유량을 이용하여 수문을 부분 개방한 경우의 월류유량을 효과적으로 산정 할 수 있는 방법을 제시하였다. 수문의 개방고와 개방도에 따라 여수로면과 수문에 작용하는 압력분포의 특성을 분석하였다. 일정한 수문 개방고에 대해 수문의 개방도가 감소할수록 그리고 일정한 개방도에 대해 수문의 개방고가 높을수록, 여수로면에서 부압은 크게 발생하며 수문에 작용하는 무차원 최대압력은 증가하는 것으로 분석되었다.

• 한국농공학회논문집
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• 제46권1호
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• pp.27-34
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• 2004

A model test is carried out to investigate flow-induced vibration of a Tainter gate in estuary sulices. The gate model scaled with the ratio of 1：25 is made of acryl panel dimensioned 0.66m in width, 0.5m in height in the concrete test flume. Firstly, natural frequencies of the model gate are measured and the results are compared with the numerical results in order to verify the model. The amplitudes of the vibration are measured under the different gate opening and water level conditions in flow from the gate outside to the gate inside. Also 5 revised gate models with bottom width increased 0.5 cm each are tested under the different gate opening and water level. The results are analyzed to study the characteristics of the gate vibration. These test results are assessed in comparison with formerly test results, as a result, presents a design method of Tainter gate to reduce the gate vibration and a basic data for the guide manuals of gate management.

• 한국수자원학회논문집
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• 제51권5호
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• pp.405-415
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• 2018

연직수문의 방류량 계산에 필요한 수리학적 변수는 유량계수, 수문개방고, 상류수심이다. 자동수문의 수문개방고는 나머지 변수에도 영향을 미치기 때문에, 운영 중 수문개방고의 거동을 예측하는 것은 정밀한 수문설계를 위해 매우 중요하다. 본 연구에서는 부력식 연직수문 모형을 대상으로 부력이론으로 계산한 수문개방고와 실험에서 방류 중에 측정한 값과의 관계로 부터, 임의의 상류수심에서 수문개방고를 예측할 수 있는 무차원 관계식을 도출하였다. 측정값이 계산 값과 차이가 나는 것은 동수압 하중에 의한 영향임을 압력계수를 이용하여 검증하였다. 유량계수는 수문개방율과의 무차원 관계식을 도출하였다. 도출된 관계식들을 홍수추적에 적용한 결과, 수문설계 시에는 동수압 하중으로 인한 수문개방 억제 효과를 충분히 고려하여야 하는 것으로 판단되었다.

• 한국농공학회논문집
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• 제54권3호
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• pp.133-139
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• 2012

Dynamic characteristic of lift gate supported by plane truss is studied by a model test scaled with the ratio of 1 : 31.25 in the four major rivers project. The vibrations of gate supported by the plane truss is assessed in comparison with those of gate supported by the space truss which was tested formerly. The gate model is made of acryl panel and calibrated by lead. A model test is conducted under the different gate opening and upstream water levels conditions in the concrete test flume dimensioned 1.6 m in width, 0.8 m in height and 24 m in length. In order to verify the model, natural frequencies of the model gate are measured, and compared with the numerical results. The vibrations of gate model supported by the plane truss in opening height of 1.0 cm~2.0 cm shows greater than one supported by the space truss. It is found that the gate model supported by the plane truss is less desirable than one supported by the space truss. thus, the latter type of gate model is requested to design.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.166-171
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• 2004

The Rate-of-Loading(ROL) effect of motor operated gate valves causes a decrease in the thrust delivered at a specific torque by the actuator under dynamic flow ${\Delta}$P conditions as compared to the no-flow, static conditions. This effect needs to be studied for the quantitative evaluation of motor operated gate valve operability. This study is performed to verify the validity for the application of ROL in the evaluation of operability of motor operated gate valves for the opening stroke. The ROL is assessed on the basis of in-situ test data for the opening and closing strokes. The results show that the distribution of the ROL for the operling sake has a tendency to the negative value when DP is higher than 150psid.

• 한국지형학회지
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• 제28권4호
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• pp.1-13
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• 2021

In this study is aerial photos and UAV(Unmanned Aerial Vehicle) images were used to analyzed the characteristics of depositional landform changes in the Geum river channels before and after the opening gate of Gongju weir. Based on the depositional landform classification result, the main stream and the bare land occupied most of the area in all periods, and also found that the main stream, mid-channel island, and sand bar occupied a greater degree of area increase or decrease compared to other landforms in the classification items. As a result of analyzing the characteristics of depositional landform changes before and after the opening gate of Gongju weir, it is judged that the depositional landforms have changed due to the decreased water level of the Geum river after the opening of the weir, the summer rainy season and typhoons, river stabilization after the effluence of Daecheong dam, supply and deposition of river sediments and fixation of vegetation. The results derived from this study can be used as basic data for the study of river depositional landforms and the establishment of management and conservation plans for the landforms in river channels.

• 한국농공학회논문집
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• 제46권2호
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• pp.41-47
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• 2004

A model test is carried out to investigate flow-induced vibration of a Tainter gate in estuary sulices. The gate model scaled with the ratio of 1:25 is made of acryl panel dimensioned 0.66 m in width, 0.5 m in height in the concrete test flume. Firstly, natural frequencies of the model gate are measured and the results are compared with the numerical results in order to verify the model. In the flow from the gate inside to the gate outside, the amplitudes of the vibration are measured under the different gate opening and downstream water level conditions. Also revised gate models with 20 mm bottom width are tested under the different gate openings and water levels. The results are analyzed to study the characteristics of the Tainter gate vibration in the sea ward flow. These test results are assessed in comparison with the results in the lake ward flow, as a result, presents the dynamic characteristics of the Tainter gate and a basic data for the guide manuals of gate management.

• 한국지리정보학회지
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• 제14권1호
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• pp.73-83
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• 2011

새만금 방조제 갑문의 개폐 상황은 새만금 인근 해역의 수질에 영향을 미치는 중요한 요소이다. 갑문의 개폐 정보는 새만금 방조제 인근 해역의 해상 탑에서 이루어지는 수질 및 유속 자료의 분석에 중요할 뿐만 아니라 해양 환경에 대한 수치 모의시 중요한 경계 조건이다. 본 연구에서는 기설치된 해상 관측 탑에 미니 노트북과 디지털카메라를 이용하여 자동무인영상 관측 시스템을 구축하고 촬영된 영상으로부터 갑문의 개폐상황을 자동으로 추출하였다. 특히 영상의 분산도 차이를 이용한 방법과 경계선 검출 기술을 동시에 활용한 결과 정확하게 갑문의 개폐 여부를 자동으로 확인할 수 있었다.