• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.769-773
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• 2010

수계별 소수력자원의 특성에 대한 연구가 수행되었다. 이를 분석하기 위하여 유량지속특성을 예측할 수 있는 모델이 개발되었고, 이를 기반으로 하여 소수력발전소의 수문학적 성능특성을 예측할 수 있는 모델이 개발되었다. 개발된 모델의 효용성을 확인하기 위하여 안동댐에서 측정된 월유입량자료를 분석하였다. 안동댐에서의 장기유입량을 분석한 결과, 본 연구에서 개발된 예측모델로부터 획득한 결과가 실측자료와 잘 일치하였다. 본 연구에서 개발된 모델은 소수력발전지점의 수력가용량과 연간출력량을 예측하는데 유용하게 사용될 수 있다는 것이 밝혀졌다. 개발된 모델을 이용하여 주요 수계에 위치한 소수력발전입지의 수문학적 성능특성을 분석한 결과 수계별로 차이를 나타냈다. 특히 북한강수계와 낙동강수계에 위치한 소수력발전입지는 다른 수계에 위치한 소수력발전입지에 비하여 비설계유량과 비출력 등에 대한 수문학적 성능에 많은 차이를 나타냈다.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.443-446
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• 2005

The Kaplan turbine model has been tested and analyzed. The blade angle and the guide vane opening of the turbine model were designed to be varied according to the best combination of guide vane and runner blade opening. When the changes in head and output were comparatively large, the efficiency drop were small, so the efficiency characteristics and stability of the entire operating condition were maintained in good condition. These results showed that the developed model in this study will be suitable for small hydro power stations with large changes in head and load.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.357-359
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• 2007

해양에너지원 중에서 파랑은 모든 해역에 폭넓게 분포하므로 가용에너지원이 풍부하고 에너지를 회수하기 위한 장치를 설치할 수 있는 해역 또한 광범위하며 반도의 지형을 지닌 우리나라의 연안 해역에 대규모로 활용이 가능한 에너지 자원중 하나이다. 본 연구는 새로운 방식인 파력발전용 횡류형터빈인 케이슨 내장형 횡류터빈을 개발하기에 앞서 파랑수조의 왕복운동을 CFD해석을 통하여 구현하는 것이다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.840-843
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• 2003

The Paper presents theoretical and experimental investigation of plunger type water hydraulic pump (plunger pump). An analysis of Crank shaft for plunger pump is carried out. With this results, the optimal dimensions of plunger pump are determined. And performance test results about slide resistance, hydraulic leak test, efficiency-pressure. and flow-speed and flow-pressure are presented.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.177-182
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• 1997

하나로(HANARO)에서 Mo-99을 생산하기 위한 LEU(Low Enriched Uranium) 표적 설계를 하였다. 표적길이 및 조사위치에 따른 Mo-99의 생성수율(Ci $^{99}$Mo/gU) 변화를 분석하였으며, 표적 설계를 위하여 표적 두께, 반경크기, 밀도, 연료물질등을 채택하여 이들에 대한 민감도 분석을 수행하였으며, 수행결과 생성수율에 가장 영향을 미치는 설계변수는 표적 두께와 밀도로 나타났다. 표적 연료로 어떤 물질을 선택하던 거의 같은 생성수율을 나타내므로 핵적으로는 같은 성능을 나타냄을 확인하였다. 또한 열수력학 조건과 연간생산량을 만족하는 표적 핵연료 집합체 설계가 가능함을 확인하였다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.104-108
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• 2012

Recently, small scale hydropower needs to be developed due to its clean, renewable and abundant energy resources. However, suitable draft of hydro-turbine body in combination with differences in wheel blade shapes is not determined yet in the range of small hydropower and it is necessary to study for the effective draft in combination with type. Therefore, watermill shaped of 250mm diameter. hydro-turbine aiming 20 watt class generator is adopted in this study because of its simple structure and high possibility of applying to small hydropower. The result shows that effective draft for the turbine body is variable concerning the size of turbine and flow rate of water. Thus, the difference of water depth between fore and aft turbine body contributes to the increase of torque, angular momentum and power output.

• The KSFM Journal of Fluid Machinery
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• v.11 no.3
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• pp.30-35
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• 2008

The purpose of this study is to examine the effect of nozzle shapes on the performance and internal flow characteristics of a cross-flow type hydro turbine for wave power generation. The performance of the turbine is calculated with the variation of rotational speed for 4 types of the nozzle shape using a commercial CFD code. The results show that nozzle shape should be designed considering available head of the turbine. Best efficiencies of the turbine by 4 types of the nozzle shape do not change largely but overall performances varies mainly by the nozzle width. The output power of the cross-flow type hydro turbine changes considerably by the nozzle shape and a partial region of stage 2 in the runner blade passage produces maximum regional output power in comparison with the other runner blade passage areas.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.6
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• pp.409-415
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• 2016

In this study, we test the effects of the surface roughness on the hydro efficiency of double-suction centrifugal pumps ($Q=70.7m^3/min$, H = 87 m). The original surface of the impeller and inner casing were coated, resulting in surface-roughness reductions ranging from $100{\sim}110{\mu}m$ to $0{\sim}0.08{\mu}m$. We conducted experimental studies to measure the efficiency of the pumps and operating-pump electro energy variations with different surface roughness values. The experimental results showed that the efficiency of the pumps increased by about 0.8~1.79% and the electric energy of the operating pump was reduced by around 4.38 ~ 6.08%. These results indicate that the performance of the pumps depend largely on the surface roughness of the impeller and inner casing, and by reducing the surface roughness, we can improve the efficiency of the pump and reduce costs by reducing the electric energy consumption.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.3
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• pp.285-291
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• 2014

This paper is related to the improvement of efficiency for high performance centrifugal pumps by reducing leakage loss, which is achieved by applying the grooved seal as a non-contact seal to the pumps. Various combinations of grooved seal types, including the spiral and the parallel groove in the rotor and/or in the stator, were tested by the experiment. And the corresponding hydraulic performance and the magnitude of axial thrust were measured and calculated for ten cases. From the results, the type with the spiral groove(spiral angle : $0.98^{\circ}$) in both the rotor and the stator was found to be most effective. In this case, the head and the efficiency were improved from the original design by 2.1% and 2.3% respectively at design capacity($340m^3/h$), and the axial thrust was decreased by 10%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.10
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• pp.773-778
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• 2015

The local heat transfer and pressure drop of developed turbulent flows in convergent/divergent channels with square axial cross-sectional areas were experimentally investigated to improve the channel design, such as a gas turbine cooling system. Square convergent/divergent channels with one ribbed wall were manufactured with a fixed rib height e of 10 mm and a ratio of rib spacing p to height e of 10. The measurement was conducted for Reynolds numbers from 15,000 to 89,000. Convergent, divergent, and straight channels with ratios $D_{ho}/D_{hi}$ of 0.75, 1.33, and 1.0, respectively, are considered. Of the three channel types, the ribbed divergent channel was found to produce the best thermal performance under identical flow rate, pumping power, and pressure loss conditions.