• Title/Summary/Keyword: Inflow conditions

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Development of Automatic Decision System for Chlorination Demand in Water Treatment Plant (정수장내 염소요구량 자동결정시스템 개발)

  • Oh, Sueg-Young
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.6
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    • pp.757-764
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    • 2002
  • Chlorination dosage in water treatment plant of field is determined by chlorination demand experiment through two or three hours after raw water was sampled in inflow. It is impossible to continuously control for real time because the sampled water is adapted chlorination dosage after water treatment process had been proceeded. Therefore in this study, we will design informal chlorination demand system, this designed system will be experimented as to water quality and accuracy of control in various conditions. Throughout these experimental results, we will revise the system and the revised system is enable to optimal control of chlorination dosage. Finally, we have developed chlorination demand system, which can automatically determination of chlorination dosage to be determined according to variety of raw water quality inflow in water treatment plant.

Simulating Daily Inflow and Release Rates for Irrigation Reservoirs(II) -Modeling Reservoir Release Rates- (관개용 저수지의 일별 유입량과 방류량의 모의 발생(II) -저수지 통관 방류량의 추정-)

  • 김현영;박승우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.2
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    • pp.95-104
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    • 1988
  • This study refers to the development of a hydrologic model simulating daily inflow and release rates for inigation reservoirs. A daily - based model is needed for adequate operation of an irrigation reservoir sufficing the water demand for paddy fields which is closely related to meteorological conditions. And the objective of this study is to develop a reservoir release rate model and then to calibrata the parameters. The release rates model considers daily water demands , water supply for transplanting, minmum release for maintaining canal flow, and maxirnun and regular flooding depth for determining effective rainfall on paddy fields. Each of the factors in the model was regarded as a lumped pararuter representing the average condition of a whole irrigated area. The water demand was estimated form the potential evapotranspiration by Penman method, the effective rainfall, and the infiltration on paddy fields. The release model was found to be capable of adequately simulating daily reservoir releases based on meteorological data.

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An Analysis of Wind Field According to the Prevailing Wind Directions for Understanding of Ventilation Passages in an Apartment Complex (아파트단지 환기경로 파악을 위한 주풍향별 바람장 분석)

  • Jung, Woo-Sik
    • Journal of Environmental Science International
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    • v.16 no.4
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    • pp.467-477
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    • 2007
  • A numerical study with Envi-met model is experimented to investigate the characteristics of wind pattern in apartment complex. In all case, most conditions such as wind speed, temperature, and surface features are considered as the same, but wind direction is the only different factor. The wind directions considered in this study have a meaning of prevailing wind direction. When the prevailing wind with the direction of $170^{\circ}$ blows into the complex, the ventilation passage toward the outside of complex is formed and the stagnation of air is not expressed. In case of having the direction of $300^{\circ}$, most evident ventilation passages are composed. When the inflow wind direction is the northeast, $30^{\circ}$, there is some possibility of stagnation phenomenon. This is because the arrangement of buildings makes a right angle with the inflow wind direction.

A Study on Flow Characteristics of Two-Dimensional Backward-Facing Step by CFD (CFD에 의한 2차원 후향계단에서의 재부착 유동특성에 관한 연구)

  • Choi Y. D.;Lee Y. H.
    • 한국전산유체공학회:학술대회논문집
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    • 1998.11a
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    • pp.127-132
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    • 1998
  • The present study is aimed to investigate flow characteristics of Two dimensional backward-facing step by numerical approach. A convection conservative difference scheme based upon SOLA algorithm is used for the solution of the two-dimensional incompressible Navier-Stokes equations to simulate the laminar, transitional and turbulent flow conditions at which the experimental data can be available for the backward-facing step. The twenty kinds of Reynolds number are used for the calculations. In an effort to demonstrate that the reported solutions are dependent on the mesh refinement, computations are performed on seven different meshes of uniformly increasing refinement. Also to investigate the result of inflow dependence, two kinds of the inflow profile are chosen for the laminar flow. As criterion of benchmarking the result of numerical simulation, reattachment length is used for the selected Reynolds numbers.

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EFFECTS OF TURBULENCE MODEL AND EDDY VISCOSITY IN SHOCK-WAVE / BOUNDARY LAYER INTERACTION (충격파 경계층 상호작용에서 난류모델 및 난류점성의 효과)

  • Jeon, Sang Eon;Park, Soo Hyung;Byun, Yung Hwan
    • Journal of computational fluids engineering
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    • v.18 no.2
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    • pp.56-65
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    • 2013
  • Two compression ramp problems and an impinging shock problem are computed to investigate influence of turbulence models and eddy viscosity on the shock-wave / boundary layer interaction. A Navier-Stokes boundary layer generation code was applied to the generation of inflow boundary conditions. Computational results are validated well with the experimental data and effects of turbulence models are investigated. It is shown that the behavior of turbulence (eddy) viscosity directly affects both the extent of the separation and shock-wave positions over the separation.

Detached Eddy Simulation of an incompressible flow past an open cavity (DES 방법을 이용한 비압축성 열린 공동 유동의 수치적 모사)

  • Chang K.S.;Park S.O.;Kwon O.J.;Constantinescu G.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.04a
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    • pp.148-152
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    • 2005
  • The three-dimensional incompressible flow past an open cavity in a channel is investigated using Detached Eddy Simulation(DES). The length to depth ratio of the cavity is 2 and the Reynolds number defined with the cavity depth is 3,360. The DES methods are based on the Mentor's SST model. In the present work, two types of inflow conditions are used; one is RANS profile, the other is LES inflow from another Large Eddy Simulation(LES) of fully developed channel flow. The results are compared with experimental data and LES results in terms of the mean statistics and temporal physics of the flow.

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Development of Automatic Decision System for Cholrination Demand in Water treatment Plant (정수장내 염소요구량 자동결정시스템 개발)

  • Oh, Sueg-Young;Lee, Sung-Ryong
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.807-812
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    • 2000
  • Chlorination dosage in water treatment plant of field is determined by chlorination demand experiment through two or three hours after raw water was sampled in inflow. It is impossible to continuously control fer real time because sampled water is adapted chlorination dosage after water treatment process had been proceeded. Therefore in this study, we will design informal chlorination demand system this designed system will be experimented as to water quality and accuracy of control in various conditions. Throughout these. experimental results, we will revise the system and revised system is enable to optimal control of chlorination dosage. Finally, We have developed chlorination demand system, which can automatically determination of chlorination dosage to be determined according to variety of raw water quality inflow in water treatment plant.

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Inflow Patterns Around a Water Intake Tower for Selective Withdrawal Depth (선택취수 수심에 따른 취수탑 유입유동 특성)

  • Cho, Yong;Kim, Yong-Yeol
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.6
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    • pp.63-70
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    • 2010
  • Shallow water withdrawal systems have been replaced with a selected withdrawal system to keep stable raw water quality in spite of occurrence of algae and muddy inflow. Before reconstruction of the water intake tower in Yongdam reservoir supplying water to Gosan water treatment facility, we have predicted flow patterns of inflowing water into the water intake tower for various withdrawal conditions. It has been predicted that the water in the withdrawal layer is significantly inflowed from the front with fast velocity into the water intake tower irrespective of withdrawal depth, while the water away from the withdrawal layer is withdrawed a little from the side with slow velocity.

Variation in the Main Kuroshio Path South of Japan

  • Sekine, Yoshihiko
    • Journal of the korean society of oceanography
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    • v.37 no.3
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    • pp.196-200
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    • 2002
  • The time variation in the Kuroshio is studied by use of nine observed distances of the main Kuroshio axis from the Japanese coast. The observed distances over 1975 - 1995 are estimated from the Prompt Report of Oceanographic Conditions published by Hydrographic Department of the Maritime Safety Agency of Japan. It is shown that large sea level difference between Naze and Nishinoomote, which represents the volume transport of the southern inflow south of Kyushu, coincides with larger distance of the Kuroshio in the upstream area from off Kyushu to off eastern Kii Peninsula and smaller distance in the downstream area from off Omae-zaki to off Boso Peninsula. In contrast, large sea level difference between Nishinoomote and Aburatsu, which represents the volume transport of northern inflow south of Kyushu, corresponds to smaller distance in the upstream area and larger distance in the downstream area. Path dynamics of the Kuroshio is discussed with reference to the variation in Volume transport south of Kyushu.

Congenital mitral valve stenosis in a Chinchilla cat

  • Lu, Ta-Li;Hung, Yong-Wei;Choi, Ran;Hyun, Changbaig
    • Korean Journal of Veterinary Research
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    • v.56 no.3
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    • pp.197-200
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    • 2016
  • A one-year-old, 3.25 kg intact male Chinchilla cat presented with acute right hind limb paralysis. Diagnostic imaging studies found cardiomegaly with interstitial lung pattern, abnormal mitral valve leaflets without maximum opening at the end of the ventricular diastole and during atrial systole and severe mitral inflow obstruction. Based on these findings and its young age, the case was diagnosed as congenital mitral valve stenosis. Treatment was directed to stabilize clinical conditions related to heart failure, to prevent further formation of thrombus and to relieve pain associated with thromboembolism. After one month of therapy, hind limb motor function was fully recovered.