• 한국유체기계학회 논문집
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• 제14권3호
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• pp.18-22
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• 2011

This paper presents the transient performance analysis of a micro-hydro Pelton turbine for the osmotic power generation using the commercially available computational fluid dynamics (CFD) code, ANSYS CFX. The detailed flow field in the micro Pelton turbine with a single-jet is investigated by the CFD code adopted in the present study. Predicted characteristic curves agree fairly well with measured data for a prototype Pelton turbine over the normal operating conditions. The computational analysis method presented herein can be effectively applied to the hydraulic design optimization process of general purpose Pelton turbine runners.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.885-890
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• 2006

This study presents analysis results for the hybrid system combining solid oxide fuel cell and gas turbine. Two different system layouts(an ambient pressure system and pressurized system) are considered and their design performance are comparatively investigated taking into account critical design factor, the most critical parameter such as turbine inlet temperature, gas turbine pressure ratio, temperature difference at the fuel cell and fuel cell operating temperature are considered as design constraints. Performance variations according to system layout and design parameters are examined in energetic view point.

• Ocean Systems Engineering
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• 제12권2호
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• pp.247-265
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• 2022

In the present study, we focus on the CFD simulations for the performance and the rotor-generated wake of a model-scale wind turbine which was designed for wave tank experiments. The CFD simulations with fully resolved rotor geometry are performed using MARIN's community-based open-source CFD code ReFRESCO. The absolute formulation method (AFM) is leveraged to model the rotating wind turbine. The k - ω SST turbulence model is adopted in the incompressible Reynolds Averaged Navier-Stokes (RANS) simulations. First, the thrust and torque coefficients, C_T and C_P, are calculated at different Tip Speed Ratios (TSR), and the results are compared against the experimental data and previous numerical results. The pressure distribution of the turbine blades at the 70% span is obtained and compared to the results obtained by other tools. Then, a verification study aiming at quantifying the discretization uncertainty of the turbine performance with respect to the grid resolution in the wake region is performed. Last, the rotor-generated wake at the TSR of 7 is presented and discussed.

• 대한기계학회논문집B
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• 제35권4호
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• pp.399-407
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• 2011

고체산화물 연료전지(SOFC)와 가스터빈을 결합한 하이브리드 발전시스템에서 가스터빈의 규모별 성능차이가 시스템의 성능에 미치는 영향에 대하여 해석하였다. 이를 위해 kW급, MW 이하급, 수 MW급 등 서로 다른 세 가지 가스터빈을 선정하여 사용하였다. 가스터빈이 순 출력을 거의 내지 못하는 kW급 시스템에서도 연료전지 단독 시스템과 비교해 효율이 증가하였으며, 가스터빈의 출력이 커질수록 (즉, 성능이 좋아질수록) 하이브리드 시스템에서 가스터빈이 차지하는 비중이 커지고 시스템의 효율이 높아짐을 확인하였다. 가스터빈의 압력비 증가에 따른 성능 변화를 살펴본 결과 세 가지 하이브리드 시스템에서 모두 출력은 증가하지만, 효율의 변화는 크지 않음을 확인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.206.1-206.1
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• 2011

Recently, various developments in the area of small hydropower have being made and small hydro turbines are suitable for domestic use because it is a clean and renewable energy source. A small hydropower generator produces power by using the different water pressure levels in pipe lines and energy which was initially wasted by use of a reducing valve at the end of the pipeline is instead collected by a tubular-type hydro turbine in the generator. In this study, in order to acquire the performance of tubular-type hydro turbine applied, the output power, head, efficiency characteristics due to the different guide vane and runner vane angle are examined in detail. Moreover, influences of pressure and velocity distributions with the variation of guide vane and runner vane angle on turbine performance are investigated by using a commercial CFD code.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.677-681
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• 2011

수직축 및 수평축 풍력터빈의 특성 및 공력성능예측 방법에 대해 고찰하였다. Darrieus형 수직축 풍력터빈은 블레이드에 유입되는 바람의 속도 및 받음각의 변화가 매우 심해 Dynamic Stall 현상이 발생하고 앞면에서 발생한 Wake가 후면 블레이드의 공력특성에 영향을 준다. 수평축은 BEMT를 활용하여 형상설계 및 성능예측이 가능하고 전산해석 및 풍동시험을 통해 공력성능예측이 수행되고 있다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.788-793
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• 2001

Test experience with a micro-turbine jet engine is introduced. The engine provides us with valuable opportunities to experience know-hows essential for engine development. It consists of a single radial compressor and a single stage turbine. Engine starting procedure has been established after many trials and errors. Static and dynamic engine performance tests were conducted. Static performance was found to be inferior to that advertised by the manufacturer. Further improvement is needed. Dynamic performance revealed that engine thrust overshoots unfavorably for the purpose of UAV control.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.372-375
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• 2007

750kW gearless type wind turbine, named U50, is developed by UNISON in Korea. The newly developed wind turbine should be evaluated the power curve and the estimated annual energy production by following international standard to verify the power performance characteristics. This paper shows the test and evaluation procedure according to IEC 61400-12-1 which specifies a procedure of measuring the power performance characteristics of a single wind turbine and applies to the testing of wind turbines of all types and sized connected to the electrical power network. And this paper also shows the power performance characteristics for U50 wind turbine which is determined in accordance with IEC regulation.

• Journal of Advanced Marine Engineering and Technology
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• 제36권3호
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• pp.351-357
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• 2012

Small hydropower is a reliable energy technology to be considered for providing clean electricity generation. Producing electrical energy by small hydropower is the most efficient contribution to renewable energy. Cross-flow turbine is adopted primarily because of its simple structure and high possibility of applying to small hydropower. The purpose of this study is to investigate the effect of inlet nozzle shape on the performance and internal flow of a cross-flow turbine for small hydropower by CFD analysis. Moreover, the shape effect of draft tube has been investigated according to modified shapes of the length and the diffuse angle. The results show that relatively narrow and converging inlet nozzle shape gives better effect on the performance of the turbine.

• 설비공학논문집
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• 제24권6호
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• pp.538-544
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• 2012

Analysis of thermal performance is required for the economic operation of turbine cycle of power plant. We developed corrective model of main feed water flow which is the most important parameter for the precise analysis of turbine cycle performance. Classification model for the identification of feed water flow measurement status was applied to increase the suitability of the corrective model. We used neural network and support vector machine to develop estimation model of main feed water flow with more generalization capability. The estimation model can be used practically to evaluate corrective performance of turbine cycle plant.