• 한국해안·해양공학회논문집
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• 제21권5호
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• pp.391-404
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• 2009

삼천포 화력발전소에서 냉각수로 이용되고 방류되는 해수를 이용한 소수력 발전소를 건설하였다. 본 연구에서는 해양소수력 발전소 건설시 가장 중요한 문제인 기존 화력발전소의 순환수 계통에 미치는 영향을 평가하기 위한 방안으로 배수로 수위의 해양소수력 건설 이전, 건설 중, 건설 이후 해양소수력 운전 상태에서의 변화를 예측한 값과 실제 계측값을 분석하였다. 설계시 일반적으로 이용되는 개수로 수리식에서부터 Flow 3D를 이용하여 3차원적인 수리해석 기법을 이용하는 것까지 다양한 예측을 시도하였고 관측을 통하여 검증하고자 하였다. 예측치와 실제 관측치의 비교 결과, 수위의 전체적인 평균값은 예측치와 관측치가 유사하였지만 수위의 변화 폭은 건설 중과 해양소수력 운전 상태에서 매우 크게 나타났다. 또한, 소수력 건설 이전에는 표준위어식과 Honma식의 예측값이 관측값과 가장 유사하였으나, 소수력 건설 이후에는 HEC-2, HEC-RAS, Flow-3D의 예측값이 실측값과 가까운 결과를 보였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 춘계학술대회 논문집
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• pp.117-122
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• 2000

In these days, the pollution of marine environment near island at Korean coastal zone caused by the trash, human waste and livestocks excreta become series problem. One of the most economic and efficient way to prevent this pollution problem is to set up island circulating incineration system. In this paper, the results of feasibility study on the application of turtle boat hull form to the incinearting vessel has been summarized especially for the resistance and course keeping point of view.

• 한국해양공학회지
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• 제11권3호
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• pp.95-99
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• 1997

In these days, the pollution of marine environment near island at Korean coastal zone caused by the trash human waste and livestocks excreata become intensified. One of the most economic and efficient way to prevent this pollution problem is to set up island circulating incineration system. In this paper, the result of feasibility study on the application of turtle boat hull form to the incinerating vessel has been summarized especially for the resistance and course keeping point of view.

• 수산해양기술연구
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• 제36권1호
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• pp.60-65
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• 2000

수중에서 운동하는 그물어구의 가상질량은 어구의 운동을 해석하고 제어하는데 중요한 파라미터이다. 본 연구에서는 트롤어구의 가상질량을 추정하기 위해서 현재 트롤 어구에서 사용되고 있는 여러 종류의 그물감을 이용해서 자루그물을 제작하여 속도제어가 가능한 회류수조를 이용하여 가상 질량이 망지의 규격 및 망사의 부피 등과 어떤 관계가 있는지를 분석하였고, 실제어구의 가상질량 계산에 적용하여 보았다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 1. 재료의 양은 같이 하고 순수하게 영각만을 달리한 각 그물에 대해 영각이 클수록 저항이 더 크게 나타났다. 2. 저항계수 (C 하(d))는 레이놀즈수(Re)에 따라 점점 감소하는 경향을 보이며, 식으로 나타내면 다음과 같았다. C 하(d)=0.039Re 상(-0.1474) 3. 망지의 표면적(TSA, Twine Surface Area)이 클수록 저항 값이 크게 나타났으며 식으로 나타내면 다음과 같다. R=21.398TSA 상(-0.4219) 4. 질량계수(C 하(M))는 유속(U)이 증가함에 따라 증가하는 경향을 나타내며 실험식은 다음과 같다. C 하(M)=37.557U-8.9684 5. 가상질량은 망사의 체적(V)과 d/l에 각각 비례관계를 나타냈다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.213-216
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• 2002

In this paper, flow patterns around two vertical cylinders were investigated numerically and experimentally Flow patterns between cylinders are very complex and interative. Changing gaps between cylinders the flow patterns are measured and numerically studied at a fixed comming velocity. The experiment has beeen conducted in circulating water channel with PIV system and manometer, and numerical analysis has been made by F.D.M. and multi block method. The results can be applied in the understanding and design of multiple pile array structures.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.84-89
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• 2000

Thermal simulation of typical stack-type and newly proposed planar-type micro-gas sensors were studied by FEM method. The thermal analyses for the proposed planar structure including temperatur distribution over the sensing layer and power consumption of the heater were carried using finite element method by computer simulation and well compared with those of typical stack-type micro-gas sensor. The thermal properties of the microsensor from thermal simulation were compared with those of a actual device to investigate the acceptability of the computer simulation.

• 한국해양공학회지
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• 제25권1호
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• pp.22-26
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• 2011

The resistance performances of a small leisure yacht with two different keels, center and double, respectively, are investigated using a model test at circulating water channel and CFD analysis. Flow patterns around the keels are observed using a tuft test to make clear the relation between the resistance performance and the flow characteristics around the keels. The results show that the keel does not affect free surface flows and that the double keel yacht has better performance compared to a single keel yacht in oblique condition from the resistance point of view.

• 한국해양공학회지
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• 제30권2호
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• pp.125-133
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• 2016

In this paper, we propose a vertical axis water turbine with dual blades. A parametric study was conducted using numerical analyses. First, a two-dimensional finite-volume analysis with a commercial code was used to find the pitch angle of the main blade under different tip speed ratio conditions. Second, we developed a potential-based panel method to find the best configuration of the inner blades. Experimental tests were conducted at the circulating water channel of Chungnam National University. Various configurations of the dual blades were considered, and their performances were comparatively investigated. The results showed that the turbine with movable dual blades produces a constant torque and tip speed ratio at various flow rates.

• 수산해양기술연구
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• 제42권2호
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• pp.86-96
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• 2006

This research aims at establishing the fundamental characteristics of the kite through the analysis of the flow field around various types of kites. The approach of this study were adopted for the analysis; visualization by PIV(particle image velocimetry). Also, the lift and drag tests of kites had been performed in our previous finding(Bae et al., 2004a; Bae et al., 2004b). For this situation, models of canvas kite were deployed in the circulating water channel for the PIV test using the same conditions as in the lift and drag tests. The results obtained from the above approach are summarized as follows: Given the rectangular and triangular kites when attack angle is $20^{\circ}$, vortex by the boundary layer separation was seen in the leading edge and the flow towards the trailing edge was more turbulent. But, the inverted triangular type kite was seen to be stable without any boundary layer separation or turbulence. The increase of the attack angle resulted in the eddy in order of the rectangular, triangular and inverted triangular type. The magnitude of the eddy followed the same order. The effect of edge-eddy was biggest in the triangular type followed by the rectangular and then the inverted triangular type. The kite as the buoyancy device or the opening device will be very useful when the appropriate applications and the stability are met.

• 신재생에너지
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• 제8권1호
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• pp.44-51
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• 2012

Due to a high tidal range of up to 10 m on the west coast of Korea, numerous tidal current projects are being planned and constructed. The turbine, which initially converts the tidal energy, is an important component because it affects the efficiency of the entire system. Its performance is determined by design variables such as the number of blades, the shape of foils, and the size of a hub. To design a turbine that can extract the maximum power on the site, the depth and duration of current velocity with respect to direction should be considered. Verifying the performance of a designed turbine is important, and requires a circulating water channel (CWC) facility. A physical model for the performance test of the turbine should be carefully designed and compared to results from computational fluid dynamics (CFD) analysis. In this study, a horizontal axis tidal current turbine is designed based on the blade element theory. The proposed turbine's performance is evaluated using both CFD and a CWC experiment. The sealing system, power train, measuring devices, and generator are arranged in a nacelle, and the complete TCP system is demonstrated in a laboratory scale.