• 한국수자원학회논문집
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• 제42권7호
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• pp.513-523
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• 2009

한강대교지점은 조석의 영향을 받고 노들섬으로 인해 흐름이 나누어지는 특수한 지형조건을 가지고 있으며, 홍수예보지점이고 한강유역의 유출량을 분석하는 대표지점이기도 하다. 따라서 정확한 수위-유량관계를 도출하기 위하여 많은 노력을 기울였으나 조석의 영향을 받지 않는 홍수기 이외의 기간에 대한 정확도의 확보가 곤란하였다. 이러한 문제를 해결하기 위한 대책으로 최근 자동유량측정에 관한 연구가 진행되었고, 실무에 적용되어 한강대교지점에서 실시간 유량자료의 획득이 가능하게 되었다. 한강대교지점에는 남단(노량진방향)과 북단(용산방향)에 2대의 자동유량측정 시설을 설치하여 운영하고 있다. 수중에 설치된 도플러방식 수평초음파유속계(H-ADCP)가 23개 각도로 회전하며 10분마다 단면의 유속자료를 생산하고, Chiu의 유속분포(Chiu, 1988)를 이용하여 유량을 계산한다. 본 고에서는 자동으로 측정된 성과와 기존의 유량측정 방법에 의한 성과를 비교하였으며, 월별 유출량에 대한 분석결과를 제시하였다.

• 한국항만학회지
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• 제14권3호
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• pp.361-371
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• 2000

A demand of marine outfall system has been much increased for the effective disposal of the wastewater due to population and industrial development at the coastal areas. The outfall system discharges primary or secondary treated effluent into the coastline, or at the deep water, or between these two. The discharge is carried out by constructing a pipeline on the sea bed with a diffuser or with a tunnel, risers and appropriate. The effluent, which has a density similar to that of fresh water, rises to the sea surface forming plume or jet, together with entraining the surrounding salt water and becomes very dilute. Thus there have been growing interests about plume behaviour around the outfall system. Plume or jet discharged from single-port or multi-port diffuser might cause certain impacts on coastal environment. Near field mixing characteristics of discharged water field using CORMIX model have been studied for effective outfall design various conditions on ambient current, depth, flow rate, effluent concentration, diffuser specification, port specification etc.. This kind of analysis is necessary to deal with water quality problems caused by the ocean discharge. The analyzed result was applied to the Pusan Jungang effluent outfall system plan.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 추계학술대회논문집
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• pp.85.2-93
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• 2000

A demand of marine outfall system have been much increased for the effective disposal of the wastewater due to population and industrial development at the coastal areas. The outfall system discharges primary or secondary treated effluent into coastline or at the deep water, or between these two. The discharge is carried out by constructing a pipeline on the sea bed with a diffuser or with a tunnel, risers and appropriate. The effluent, which has a density similar to that of fresh water, rises to the sea surface forming plume or jet, together with entraining the surrounding salt water and becomes very dilute. Thus there have been growing interests about plume behaviour around the outfall system. Plume or jet discharged from single-port or multi-port diffuser might cause certain impacts on coastal environment. Near field mixing characteristics of discharged water field using CORMIX model with has been studied for effective outfall design various conditions on ambient current, depth, flow rate, effluent concentration, diffuser specification, port specification etc.. This kind of analysis is necessary to deal with water quality problems caused by the ocean discharge. The analyzed vesult was applied to the Pusan Jungang dffluent outfall system plan.

• 한국유체기계학회 논문집
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• 제18권6호
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• pp.45-56
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• 2015

This paper aims to develop a submerged propeller turbine for micro hydropower plant which allows to sustain high values of efficiency in a broad range of hydrological conditions (H=2~6 m, $Q=0.15{\sim}0.39m^3/s$). The two aspects to be considered in this development are mechanical simplicity and high-efficiency operation. Unlike conventional turbines that have spiral casing and gear box, this is directing driving and no spiral casing. A 10 kW class turbine which has the most high potential of the power generation has been developed. The most important element in the design of turbine is the runner blade. The initial blade is designed using inverse design method and then the runner geometry is modified by classical hydraulic method. The design process is carried out in two steps. First, the blade shape is fix and then other components of submerged propeller turbine are designed. Computational fluid dynamics analyses based on the Navier-Stokes equations have been used to obtain overall performance data for the blade and the full turbine, respectively. The results generated by performance parameters(head, guide vane opening angle and rotational speed) variations are theoretically analysed. The evaluation criteria for the blade and the turbine performances are the pressure distribution and flow's behavior on the runner blades and turbine. The results of simulation reveals an efficiency of 91.5% and power generation of 10.5kW at the best efficiency point at the head of 4m and a discharge of $0.3m^3/s$.

• 한국방재학회 논문집
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• 제4권3호
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• pp.43-50
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• 2004

본 연구에서는 갈수시 하천에 순간적으로 유입되는 오염물질에 대해 댐방류량 변화에 따른 플러싱 효과를 분석하였다. 한강하류부(잠실수중보${\sim}$신곡수중보)에 RMA-2 및 RMA-4 모형을 적용하였으며, 유로특성을 반영할 수 있도록 종확산계수는 $50m^2/s$을 사용하였다. 댐방류량은 1시간동안 $500m^3/s,\;1000m^3/s,\;1500m^3/s,\;2000m^3/s$로 변화시켰으며, 갈수시 유량은 $200m^3/s$로 고정하였다. 정체되어 있는 경우와 순간적으로 유입되는 경우, 성산대교 부근에서 농도가 1ppm 이하로 떨어지는 시간을 각 유량별로 분석하였다. 댐방류량이 증가할수록 희석시간이 단축되는 것을 알 수 있었고, 댐방류량과 희석시간이 선형관계가 있는 것으로 나타났다. 순간적으로 유입된 오염물질이 정체된 오염물질의 경우보다 댐방류량에 민감하게 영향을 받으며, 댐방류량에 의한 플러싱을 시도할 경우에는 본류의 오염물질이 지류로 역류하는 범위를 파악할 수 있었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.408-412
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• 2006

단면평균 1차원 수치모형의 수중구조물 표현방식으로 흔히 사용되는 월류공식의 유량계수를 범용 난류유동 수치모형인 FLUENT를 사용하여 완전월류와 불완전월류의 전구간에 걸쳐 구하고 공식화한 결과를 제시한다. 수중구조물은 고무댐과 Ogee형 월류보의 2가지를 대상으로 하였다.

• 상하수도학회지
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• 제33권4호
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• pp.243-250
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• 2019

This objective of this study was to investigate the degradation characteristics of phenol, a refractory substance, by using a submerged dielectric barrier discharge (DBD) plasma reactor. To indirectly determine the concentration of active species produced in the DBD plasma, the dissolved ozone was measured. To investigate the phenol degradation characteristics, the phenol and chemical oxygen demand (COD) concentrations were evaluated based on pH and the discharge power. The dissolved ozone was measured based on the air flow rate and power discharged. The highest dissolved ozone concentration was recorded when the injected air flow rate was 5 L/min. At a discharge power of 40W as compared to 70W, the dissolved ozone was approximately 2.7 - 6.5 times higher. In regards to phenol degradation, the final degradation rate was highest at about 74.06%, when the initial pH was 10. At a discharged power of 40W, the rate of phenol decomposition was observed to be approximately 1.25 times higher compared to when the discharged power was 70W. It was established that the phenol degradation reaction was a primary reaction, and when the discharge power was 40W as opposed to 70W, the reaction rate constant(k) was approximately 1.72 times higher.

• 한국농공학회지
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• 제14권3호
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• pp.2716-2725
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• 1972

Side channel spillways based on Hinds theory were tested. Surface water level at the beginning point of side channel is the same as the crest level of weir in the usual design. Here, side channel section were moved upwards $\frac{1}{2}$ of the total head on the crest and test(revised experiment) were made. In the revised experiments, coefficients of discharge for design flood (Q) were the same with that of original design experiments. In case of 1.2Q a little influence of submergence were appeared, coefficients of discharge were decreased to be about 97.6% of that of original design experiments, therefore, Reservoir flood water level become higher about 2-3cm than original case. So revised design can be used for actual purpose and it will brings much savings in construction cost of side channel spillway.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2018년도 춘계학술대회
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• pp.234-236
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• 2018

기후변화는 더 이상 피할 수 없는 매우 중요한 문제다. 온실가스 중 큰 비중을 차지하는 이산화탄소 배출을 억제하거나 제거하기 위한 많은 연구들이 진행되고 있다. 최근에는 CCS 중 하나인 지중저장(underground storage)의 대안으로 해양에 이산화탄소를 저장하는 기술인 AWL(Accelerated Weathering of Limestone)을 이용한 해양저장(ocean storage)에 대한 연구가 진행되고 있다. AWL은 이산화탄소를 중탄산이온 형태의 농축수로 만들어 해양에 방류하여 희석 저장시키는 방법으로, 대기 중 재방출이 거의 발생하지 않고 배출된 농축수는 해양의 알칼리도를 높여 해양산성화를 방지할 수 있는 장점이 있다. 금회 연구는 AWL에 의한 방법 중 중탄산이온 농축수의 해양방류 시 이산화탄소 등을 포함하는 용존 무기탄소(DIC, Dissolved Inorganic Carbon)의 거동특성을 파악하기 위한 목적으로 수행하였다. 연구대상 해역은 충분한 수심과 작업효율성이 확보되는 울릉도 부근으로 설정하였으며, 거동특성을 파악하기 위하여 표층방류(surface discharge)와 수중방류(submerged discharge)에 의한 물질확산을 계산할 수 있는 CORMIX모형을 채택하였다. 실험결과, 방류 시점으로부터의 희석률을 고려했을 때, 표층방류 시나리오가 농축수 방류에 가장 적합한 방식이라고 사료된다.

• 상하수도학회지
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• 제34권2호
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• pp.93-104
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• 2020

As water resources are limited and legal regulations are strengthened, there is a growing need to reuse residuals in WTP(Water Treatment Plant). In this study, membrane filtration system was constructed and its operation method was studied for water quality stabilization and reuse of WTP residuals. The operation parameters were stable for 1 year and 6 months. Membrane fouling was identified as particulate pollution (activated carbon) and inorganic pollution (manganese). The membrane system was operated steadily with raw water of high concentration SS(Suspended solid) containing activated carbon because membrane fouling was reduced by the effect of End-Free type. In the case of inorganic contamination, dissolved manganese eluted by chemicals and acted as a membrane fouling source, and the operating conditions for minimizing membrane fouling. were confirmed by newly developing application methods and types of cleaning chemicals. Based on the results, design parameters for reducing manganese membrane fouling were derived.