• Water for future
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• 제6권1호
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• pp.29-35
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• 1973

For the simplicity in the analytical solution, the simple surge tank has been chosen for the test where an unsteady flow is porduced by suddenly closing the valve controlling the discharge. The valve is loated immediately downstream from the surge tank. Momentumn equations in the penstock and in the surge column are measured recored on the oscillograph and then the calibration of surge column heights and scale readings on the oscillograph trace are made. The diameter of the penstock are determined by the trial and error method. The water levels in the surge column are computed by numerical integration of the differential equation of the surge tank. The relationships between the results from the experiment and numerical computation are figured, compared and discussed.

• Journal of the Korean Society of Safety
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• 제31권5호
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• pp.67-73
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• 2016

This study investigates the seismic performance of the surge tank which is of the atmospheric type and constructed above the ground. For that purpose, three different numerical models of the surge tank have been taken into account. Two models are constructed to describe the surge tank with different support conditions: one is to model all supports as fixed, and the other is to use spring element for the rock conditions. The third model is constructed to describe not only the surge tank with spring element of the rocks but also the vertical waterway tunnel. Through the time-history analysis of the surge tank subjected to three artificially excited ground motions, it is demonstrated that there can be much difference between the three models of our interest according to the support conditions and inclusion of the vertical waterway tunnel. However, their seismic performances still remain below the safety criteria, i.e., dynamic allowable stress. Also, the numerical results let us know where the critical sections occur. These results could be used to develop the efficient seismic enhancement method for the surge tank.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.441-444
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• 2007

Surge tank generally are used near the downstream end of tunnels of penstocks to reduce change in pressure caused by waterhammer resulting from load changes on the turbines. In this paper, the surge tank with chamber is selected to analyze water surface oscillation. the governing equation are derived using the law of conservation of mass and momentum. the water surface oscillation in the surge tank are computed using governing equation. In the case of upsurging, water surface oscillation is damped gradually and in the case of downsurging, it is damped rapidly.

• Journal of Korea Water Resources Association
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• 제42권10호
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• pp.785-793
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• 2009

Numerical model which can simulate the surge tank for unsteady flow was developed in the present study. Furthermore, reliability model which can calculate the probability of pipe breakage regarding unsteady effect was developed. For the risk estimation of pipe breakage and functional estimation of surge tank, probability of pipe breakage for pipe network with surge tank was calculated regarding unsteady effect. From the results, it was found that unsteady flow significantly increase the probability of pipe breakage and surge tank considerably decrease probability of pipe breakage as damping out the pressure oscillations.

• Journal of the Korea institute for structural maintenance and inspection
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• 제11권2호
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• pp.164-174
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• 2007

Phenomena of hydraulic transient such as water hammer should be analyzed to design the pipeline systems effectively in dam. Surge tanks generally are used to reduce change in pressure caused by hydraulic transient from load changes on the turbines. In this study, the appropriate scale of surge tank with chamber is investigated for dam safety management. The variation of water level in the surge tank are computed using governing equation. Using the Thoma-Jaeger's stability condition, static and dynamic stability are investigate for the cases of flood water level, normal high water level, rated water level and low water level. Finally appropriate diameters of shaft and chamber are determined in the surge tank with chamber.

• Journal of the korean Society of Automotive Engineers
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• 제12권3호
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• pp.3-8
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• 1990

본 고에서는 자동차의 냉각장치중, 냉각수를 저장하는 기능을 갖는 surge-tank의 내압에 의한 국부적인 균열 발생 방지 및 용기의 응력환화를 목적으로, 범용 구조해석 프로그램인 CAEDS의 여러 모듈(GEOMOD, GFEM, IFES, OPTISEN)을 이용하여 응력해석을 수행한 후, OPTISEN(최적화 해석 모듈)을 적용하여 용기 두께 및 보강재 위치에 따른 설계민감도를 구하여 최적 두께 및 보강재의 최적 위치를 구하였다.

• Journal of Korean Society of Water and Wastewater
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• 제23권3호
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• pp.295-303
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• 2009

In the present study, a reliability analysis calculating the probability of system failure has been performed using cut set and results of numerical analysis for unsteady flow in pipe. Especially, the probability of system failure has been evaluated regarding the effect of valve closure which is a really important activity in operation of piping system. In spite of small amount of demand, it was found that fast valve closure can generate high probability of system failure. Furthermore, it was confirmed that surge tank can reduce the unsteady effects and probability of system failure in water distribution system. From the results, it was found that the unsteady flow has a significant effect on the probability of system failure Furthermore, it was able to find which pipe or cut set has high probability of system failure. So it could be used to determine which pipe or cut set has a priority of repair and replacement. Therefore, reliability analysis regarding unsteady flow has to be performed for the planning, designing, maintenance, and operation of piping system.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• 제13권1호
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• pp.69-74
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• 2017

In the fire protection system or fire fighting water supply system, the jockey pump is generally installed for the prevention of the pressure decrease of pipes, the frequent driving of the fire pump and protection the pipes from the water hammer. In this paper, the pressure-rise in fire fighting water distribution pipes in condition of pipe pressurization by the surge tank at the start-up and the sudden-stop of the fire pump without additional installation of jockey pump is considered by using simple formula calculations and the evaluation of water hammer occurrence in condition of pipe pressurization by the surge tank is included. As a result, the pressure-rise of pipes is less than the pipe design pressure at the condition of pump's start-up and sudden stop, and the possibility of water hammer occurrence is remarkably low due to pressurization of the pipes by the surge tank.

• International Journal of Fluid Machinery and Systems
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• 제5권4호
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• pp.152-160
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• 2012

Model tests and CFD were carried out to find out the cause of cavitation surge in hydraulic power plants. In experiments the cavitation surge was observed at flow rate, both with and without a surge tank placed just upstream of the inlet volute. The surge frequency at smaller flow rate was much smaller than the swirl mode frequency caused by the whirl of vortex rope. An unsteady CFD was carried out with two boundary conditions: (1) the flow rate is fixed to be constant at the volute inlet, (2) the total pressure is kept constant at the volute inlet, corresponding to the experiments without/with the surge tank. The surge was observed with both boundary conditions at both higher and lower flow rates. Discussions as to the cause of the surge are made based on additional tests with an orifice at the diffuser exit, and with the diffuser replaced with a straight pipe.

• Water for future
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• 제17권1호
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• pp.45-56
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• 1984

The whole process from the model design to the results of the test, of hydraulic model test of restricted entry surge tank of Hapcheon dam, is reviewed with the respect to the flowchart of the experiment. And the experimental results are compared with the numerical values which are calculated by Runge-Kutta-Gill scheme. The comparision show a reasonable agreement. In final design, it doesn't matter that only numerical values are considered in case of the short design period, or difficulties of budget, and or the comparably simple type surge tank as Hapcheon dam.