• Journal of Advanced Marine Engineering and Technology
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• v.24 no.4
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• pp.486-493
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• 2000

Flow mechanism around air flow sensor of electronic control engine, especially Karman vortex type, was investigated experimentally. The two-dimensional flow characteristics in the intermediate wake region behind a triangular vortex-generator respectively apex forward facing, apex backward facing and vertical flat plates following after apex forward facing(i.e vortex-flowmeter) were investigated at Reynolods number of $ReH=1.4\times10^4$; H is the width of a triangular vortex-generator. The vortex shedding frequency for wide Reynolds number from $7\times10^3$ to $2.1\times10^4$ was also surveyed. The velocity component was measured by X-type hot wire anemometer at 8H downstream from the bluff body. The coherent structure of the intermediate wake behind a bluff body was obtained by conditional phase average technique. As a result, it was verified that the vertical flat plates following after apex forward triangular vortex-generator make not only more linear relation between free stream velocity and vortex shedding frequency but also more periodic vortex in the vicinity of the center of wake.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.157-162
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• 2012

A structural modification of baseframe is an effective method to avoid resonance in marine diesel generator (D/G) set which consists of diesel engine, generator and baseframe. However the reinforcement with thick plates or additional parts to increase the natural frequency can be less effective because of increased weight. Especially fine control of target mode based on the experience is difficult because the weight and interference of system have to be considered. In this paper, the design optimization of baseframe was performed to reduce the resonant vibration using a gradient descent method. The design parameters such as thickness, shape and location of baseframe parts are optimized to increase the torsional natural frequency of D/G set. From the actual test, the new designed baseframe reduced the vibration level in resonance by 55% without any increase of weight and interference. interference.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.3
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• pp.44-54
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• 1996

The release of polluting gases such as NO/sub x/ of SO/sub x/ to the atmosphere from ships is causing increasing concern. To reduce destruction to the marine environment, the value of the utilization of photovoltaic energy is highly appreciated since photovoltaic energy is and alternate clean energy source to fossil fuels. The use of a photovoltaic generating system to supplement diesel engine driven electric power system on ships has been studied. The design of the photovoltaic generating system based on a photovoltaic array is presented in this paper. The amount of NO/sub x/ and SO/sub x/ emission is found to be significantly reduced for a small vessel operated within a harbour after a photovoltaic generating system is installed to supplement the diesel engine generator system.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.3
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• pp.176-176
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• 1996

The release of polluting gases such as NOx of SOx to the atmosphere from ships is causing increasing concern. To reduce destruction to the marine environment, the value of the utilization of photovoltaic energy is highly appreciated since photovoltaic energy is and alternate clean energy source to fossil fuels. The use of a photovoltaic generating system to supplement diesel engine driven electric power system on ships has been studied. The design of the photovoltaic generating system based on a photovoltaic array is presented in this paper. The amount of NOx and SOx emission is found to be significantly reduced for a small vessel operated within a harbour after a photovoltaic generating system is installed to supplement the diesel engine generator system.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.7
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• pp.907-913
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• 2011

Swirling flows are related to the spiral motion in the tangential direction in addition to the axial and radial direction using several swirl generators. These type of flows are used in combustion chambers to improve flame stability, heat exchanger to enhance heat transfer coefficients, agricultural spraying machines and some vertical pipes to move slurries or transport of materials. However, only a few studies three dimensional velocity profiles in a vertical pipe have been reported. In this present paper, 3 dimension particle image velocimetry(PIV) technique was employed to measure the velocity profiles in water along a vertical circular pipe with Reynolds number from 6000 to 13,000. A tangential inlet condition was used as the swirl generator to produce the required flow. The velocities were measured with swirling flow in the water along the test section using the PIV technique.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.1
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• pp.31-40
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• 2000

This paper describes the numerical computations of the interaction between the streamwise vortex and a flat plate 3-D turbulent boundary layer. In the present study, the main interest is in the behavior of the streamwise vortices introduced in turbulent boundary layers. The flow behind a vortex generator is modeled by the information that is avilable from studies on the dalta winglet. An algorithm of the solution of the incompressible Navier-Stokes equations for three-dimensional turbulent flows, together with a two layer turbulent model to resolve the near-wall flow, is based on the method of artificial compressibility. The present results show boundary layer distortion due to vortices, such as strong spanwise flow divergence and boundary thinning, and have a good agreement with the experimental data.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.6
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• pp.915-922
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• 2008

The gas separation technology using membrane is widely used to refine various gases in many industry fields and recently is being applying in $CO_2$ recovery technology. In the gas and chemical tanker. nitrogen generators for inerting, purging and padding are on board and most of them have membrane modules of hollow fiber type with long life and vibration resisting properties. Because a membrane module is a key component accounting for 50% of total manufacturing cost of nitrogen generator, adequate selection for it is an important problem. In this paper, the flow performance coefficient based on dimension and specification data of membrane module was relatively selected to compare nitrogen generating capacity of module and various performance tests about the selected PARKER ST6010 membrane module were conducted. As a result, the useful coefficient and basic data in selecting a membrane module were achieved.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2002.05a
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• pp.245-250
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• 2002

The operational data of diesel generator engine is two kind of discrete signal and analog signal. We can find the fault information from analog data measured for every sampling time if it is invested the changing rate or direction of data. This paper propose the Malfunction Diagnosis Engine(MDE) using the commercial data mining tool and show the data Process and fault finding method with the data collected from generator engine of the ship.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.3
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• pp.311-319
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• 1999

In Korea accelerated industry development and urbanization during the last three decades have led serious water pollution problems in many parts of the nation. Especially in the regions of west and south coast have low fresh water in the dry season of spring and summer. In the place isolated from land it is important to secure the fresh water for drinking and general service. This study is concerned on the thermal system design to develop low-pressure evaporation type fresh water gen-erator of capacity 1 ton/day using the heat source of non-operating boiler in the season of spring and summer. The results obtained from this study are as follows. the water quantitieds generated from experi-mental evaporator showed good coincidence with the calculated values. The maximum production quantity was 1.38ton/day at pressure 40mmHg abs. and temperature $80^{\circ}C$.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.221-221
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• 2017