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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean society of Fisheries Technology
Journal Basic Information
Journal DOI :
The Korean Society of Fisheries Technology
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Volume & Issues
Volume 28, Issue 4 - Dec 1992
Volume 28, Issue 3 - Sep 1992
Volume 28, Issue 2 - Jun 1992
Volume 28, Issue 1 - Mar 1992
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The Pattern of Sea Water Circulation in Kamak Bay
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 117~131
A studies on the pattern of sea water circulation was carried out by using drogue experiments, tidal current measurement and hydrographic data in Kamak Bay which has two channels. At the flood, the water inflowed from the northern narrow channel flows mostly to the southward then the westward because Daekyung-island located at the flow path, at the same time the water from the southern channel of bay directed strongly to the north with a spine centered at around Gunnaeri. And these waters converged at the area between eng-Island and Deakyung-Island in the bigining of the flow, and placed at less southern part than the area at the late. The water of the north west inner bay having concave bottom topography inflows to Najin inlet with a spin of anti-clockwise. At the ebb, those waters in the bay turn back to two channels respectively, but most of waters directed to the southern channel of the bay. The directions of residual current of two channels are the southward mainly, and the current of inner area are influenced by the prevailing wind. The north-west inner bay which has the weak tidal current less than 10 cm/sec shows a similar upwelling by off-shore wind in winter, and the stratification in summer, respectively.
Computational Fluid Analysis for the Otter Boards
Go, Gwan-Seo ; Gwon, Byeong-Guk ; No, Gi-Deok ;
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 132~143
This paper presents a method in order to calculate the vortex distribution, the streak-line and the time-line around the flat and the cambered otter board in two dimensional flow using the discrete vortex method, and to calculate C sub(L) and C sub(D) of the otter boards varied with the passage of time by the numerical simulation using the Blasu's formula. The results obtained are summarized as follows: 1. Flow pattern around the otter boards calculated by the discrete vortex method was resembled closely that of the visualized photograph. 2. C sub(L) and C sub(D) calculated by the numerical simulation was very similar to the model test. 3. The circulation direction around the otter boards and the action direction of the shearing force can be recognized from the time-line around the otter boards. 4. Flow speed in the back side of the otter boards was faster than that in the front side, and the difference of the flow speed in both side of the cambered otter boards was about 1.3 times greater than that of the flat otter boards. 5. The clockwise vortex was generated in the trailing edge, and the counter-clockwise vortex was generated the leading edge of the otter boards. And they were shown the shape of Karman's vortex varied with the passage of time.
A Study on Defect Diagnosis of Rotating Machinery Using Neural Network
Choe, Won-Ho ; Yang, Bo-Seok ;
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 144~150
This paper describes an application of artificial neural network to diagnose the defects of rotating machiner. Induction motor was used to the object of defect diagnosis. For defect diagnosis, the frequency spectrum of vibration was utilized. Learning method of applied neural network was back propagation. Neural network has following advantage; Once it has been learned, inference time is very short and it can provide a reasonable conclusion regardless of insufficient input data. So, this defect diagnosis system can be used superiorly to rule based expert system as quality inspection of rotating machinery in the shop.
A Study on Flowfield and Pressure Recovery in a Conical Diffuser with a Swirl Flow
Jeong, Hyo-Min ; Koh, Dae-Kwon ; Yang, Jung-Kyu ;
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 151~156
The purpose of this paper is to investigate the relationship between static pressure recovery and velocity distributions in case of swirling flow into a conical diffuser. In this research, velocity distribution is measured by a multi-hole yaw-meter. The following conclusions can be drawn from the experiments. (1) The static pressure recovery depends strongly on the strength of a swirl. (2) A high pressure recovery coefficient is achieved by inserting a solid core into the diffuser center.
A Study on Pressure Loss and Turbulent Charactristics in a Conical Diffuser with a Swirl Flow
Jeong, Hyo-Min ; Koh, Dae-Kwon ; Yang, Jung-Kyu ;
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 157~163
In this paper, the relationship between static pressure recovery and turbulent energy was presented in case of swirling flows into a conical diffuser. The distributions of turbulent energy in a diffuser sectional area were measured by a hot wire anemometer. The following conclusion can be drawn from the experiment. Diffuser loss is constituted by a dynamic pressure loss and total pressure loss. The static pressure recovery depends strongly on the total pressure loss. The static pressure recovery depends strongly on the total pressure loss, and the turbulent energy varies inversely as the static pressure recovery coefficient.
An Experimental Study on the Uniform Droplet Production Regions of Light Oil Blended with Fish Oil
Jang, Jae-Eun ; Ahn, Soo-Kil ;
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 164~170
In order to understand and explain the spary combustion, it was necessary to understand the disintegration mechanisms of liquid jet. To understand the disintegration mechanisms of liquid jet, the disintegration phenomena and uniform droplet production regions of testing liquid jet was investigated by means of longitudinally vibration capillary nozzle, which was injected the testing liquids. The testing liquids were light oil and light oil and light oil blended with 25wt% fish oil (File fish oil, Sardine fish oil, Alaska pollac oil) The results can be summarized as follows: 1. The uniform droplet phenomena have been changed according to the frequency of capillary tube, the jet velocity and physical properties of testing oils. 2. Within the region of uniform droplet, Reynold number was increased as Weber number increases. 3. The lower limit of wave length in which uniform droplet was produced 0.8d which was lower than Rayleigh wave length 4. The light oil blended with file fish oil which has lower viscosity and surface tension had the widest uniform droplet production region on the frequency and velocity among testing oils. But light oil blended with sardine fish oil were similar with light oil in the uniform production region.
A Study on the behaviour of Cavitation erosion and lubricating Oils and the influence of Corrosion on Slide Bearing Metals for Internal combustion Engine
Lee, Jin-Yeol ; Im, U-Jo ;
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 171~183
In this paper, the behaviour of cavitation erosion, influence of corrosion and corrosion control on slide bearing metals for internal combustion engine were investigated, and this experiment was done by the vibratory cavitation erosion tester. The main results obtained are as follows: 1. With decreasing the space between horn and specimen, the weight loss and its rate increased step by step. But the weight loss and its rate of 0.2mm space decreased conversely more than that of 0.4mm space at early stage. 2. The weight loss and its rate with change of pH were appeared to the order of pH2>pH12>pH7>pH4. And the weight loss and its rate at pH 4 decreased at best. 3. The weight loss and its rate by cavitation erosion for bearing metals were shown to the order of W.M7>W.M1>K.M4. 4. There appeared mainly small pit hole at pH2, and appeared the pit of netting thread type at pH12 by the results of the damaged surfaces at pH2 and pH12 environments that were sensitive to cavitation erosion. 5. With increasing the viscosity of lubricating oil, the weight loss rate by cavitation erosion became dull at the space below 0.5mm. 6. The protective efficiency of cavitation erosion-corrosion is superior inhibitor of chormate(25 ppm) to cathodic protection.
Combustion Characteristics of Fish Oil in a Constant Volume Combustion Bomb
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 184~190
The combustion characteristics, ignition delay, p-t, dp/dt, Q-t of diesel oil and fish oil blended diesel oils was investigated according to pressure and temperature in a constant volume combustion bomb. The results are as follows: 1) The influence of temperature and pressure on the ignition delay was almost constant in high temperature, regardless of the blending rates, and the ignition delay was shortest in the 60% blend. 2) The maximum pressure was high in order of with pure diesel oil, with the 20% blend and the 60% blend. 3) The rate of pressure rise was high in order of with pure diesel oil, with the 20% blend and the 60% blend. The rate of maximum pressure rise was significantly higher with pure diesel oil than with two blends. 4) The amount of accumulative heat release was large in order of with pure diesel oil, with the 20% blend and the 60% blend.
On the Performance Improvement of the Diesel Engine by Uitrasonic Treatment of Fuel Oil
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 191~196
This paper is an experimental study to investigate utility of ultrasonic treatment of fuel oil in diesel engine. Experiment was carrid out to clarify the effect of ultrsonic vibration on the characteristics of maximum pressure, fuel consumption ratio, smoke, BMEP and torque. The result obtained are as follows: 1. In the case of given ultrsonic vibration, the maximum pressure is increased in all experimental conditions. 2. In the case of given ultrsonic vibration, the decrease effect of fuel consumption rate is increased at low rpm. 3. The generation quantity of soots is increased according to load. In the case of given ultrsonic vibration, the decreased quantity of soots does not very according to load. 4. In the case of given ultrsonic vibration, the BMEP and torque are increased at low load.
The Fatigue Life and Penetration Behavior by Variety of Aspect Ration on Smooth Specimen
Nam, Ki-Woo ; Um, Yoon-Sung ;
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 197~207
Fatigue life and penetration behavior were examined analytically by variety of initial front face crack length and initial crack depth. The fatigue crack shape before penetration is almost semielliptical, and the aspect ratio by calculation using the Newman-Raju's formula is smaller than the value obtained by the experiment. It is found that the crack growth behavior on the back surface after penetration is unique and can be divided into three stage a, b and c. By using the K value proposed by the authors, particular crack growth behavior and the change in crack shape can be evaluated quantitatively. It is found that fatigue life and penetration behavior were more dependent on initial front face crack length than initial crack depth.
( Control of Primary Solidification Mode for Improving Solidification Cracking Resistance , Corrosion Resistance and Cryogenic Toughness of Austenitic Stainless Steel
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 208~215
Concept of primary solidification mode control was adopted to obtain optimal solidification crack resistance, hot ductility, corrosion resistance and toughness for austenitic stainless steel. By controlling primary solidification phase as primary
and containing no ferrite at room temperature, optimal solidification crack resistance, hot ductility, corrosion resistance and cryogenic toughness could be obtained. The optimum chemical composition of austenitic stainless steel ranges 1.46~1.55(Creq/Nieq ratio) calculated by Schaeffler's equation.
Study on the Corrosion Charactristics and its Corrosion Protection of Steel Fishing Banks
Lim, Uh-Joh ; Lee, Jong-Rark ;
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 216~227
The corrosion rate, behavior of corrosion fatigue and characteristic of cathodic protection for SB41 were investigated by corrosion and corrosion control tests in seawater at laboratory and coast. The main result obtained are as the following; 1) The corrosion rate of base metal (BM) is about 28-37 mg/dm super(2) day in seawater of coast. 2) The correlation between the stress intensity factor range
K and crack propagation rate da/dN for weldment follows paris' rule in seawater : da/dN=C(
K) super(m) where m is the slope of the correlation, and is 2.02 for BM and 1.75 for heat affected zone (HAZ) respectively. 3) The corrosion sensitivity of HAZ is more sensitive than that of BM under the low region of
K. 4) With increase of bared surace area of cathode, cathodic protection potential is increased sharply.
Numerical Analysis on the Wave Resistance for Development of Ship`s From of Tuna Purse Seiner
Journal of the Korean society of Fisheries Technology , volume 28, issue 2, 1992, Pages 228~239
The purpose of the present research is to develop an efficient numerical method for the calculation of potential flow and predict the wave-making resistance for the application to ship design of tuna purse seiner. The paper deals with the numerical calculation of potential flow around the series 60 with forward velocity by the new slender ship theory. This new slender ship theory is based on the asymptotic expression of the Kelvin-source, distributed over the small matrix at each transverse section so as to satisfy the approximate hull boundary condition due to the assumption of slender body. Some numerical results for series 60, C sub(b) =0.6, hull are presented in this paper. The wave pattern and wave resistance are computed at two Froude numbers, 0.267 and 0.304. These results are better than those of Michell's thin ship theory in comparison with measured results. However, it costs much time to compute not only wave resistance but also wave pattern over some range of Froude numbers. More improvements are strongly desired in the numerical procedure.