• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.371-374
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• 2006

Heat transfer characteristic near a sharp fin in a supersonic flow was studied. Infra-red thermography was used to obtain the variation of surface heat transfer coefficient distribution. The attack angle of fin is ranged from $10^{\circ}\;to\;20^{\circ}$ and the oil flow method was also conducted to understand a flow field near a sharp fin.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.10
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• pp.927-933
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• 2007

Heat transfer characteristic near a sharp fin was studied in a supersonic flow. Mach number and the Reynolds number were 3 and $5{\times}10^7$ respectively. Infra-red thermography was used to obtain the variation of surface heat transfer coefficient distribution. The angles of attack were ranged from $12.5^{\circ}$ to $20^{\circ}$ and the numerical analysis and the oil flow method were conducted to understand flow fields near a sharp fin.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.8
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• pp.728-740
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• 2004

Heat sink has extended surface area for enhanced heat transfer. The enhanced convection heat transfer has been used widely, such as cooling electronic chips in the electronics industry. Heat sink usually requires an increase in the heat transfer and a decrease in the pressure drop, and must improve the performance in the flow field of industrial plants. In this study, wing fin heat sink was studied and tests were conducted in a rectangular cross sectional channel with wing fin heat sinks. The leading and trailing ends of a wing fin have a sharp edge, simulating the airfoil feature. Empirical correlations have been developed for wing fin heat sink types. And wing fin heat sinks have better cooling performance than elliptic fin and square fin types.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.185-190
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• 2005

This work presents a numerical procedure to optimize the elliptic-shaped pin fin arrays to enhance turbulent heat transfer. The response surface method is used as an optimization technique with Reynolds-averaged Navier Stokes analysis of flow and heat transfer. Shear stress transport (SST) turbulence model is used as a turbulence closure. Computational results for average heat transfer rate show a reasonable agreement with the experimental data. Four variables including major axis length, minor axis length, pitch and the pin fin length nondimensionalized by duct height are chosen as design variables. The objective function is defined as a linear combination of heat transfer and friction-loss related terms with weighting factor. D-optimal design is used to reduce the data points, and, with only 28 points, reliable response surface is obtained. Optimum shapes of the pin-fin arrays have been obtained in the range from 0.0 to 0.1 of weighting factor.

• Animal Systematics, Evolution and Diversity
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• v.28 no.4
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• pp.304-307
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• 2012

A three specimen of Icelus toyamensis, belonging to Cottidae, Scorpaeniformes, was firstly collected from the East Sea, Korea during 2007-2009. We herein described the species as the first record from Korea on the basis of these specimens. Icelus toyamensis is characterized by the following morphological combinations: spinous scales absent on the base of dorsal fin; small ctenoid scales scattered on body sides; gill rakers are short, tubular, and relatively broad; the uppermost preopercular spine is sharp and simple; dorsal fin rays VIII-IX, 20-21; anal fin soft rays 18-19; pectoral fin rays 18, and vertebrae 40-41. New Korean name of I. toyamensis is proposed as "Min-jul-ga-si-hoet-dae."

• Korean Journal of Ichthyology
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• v.29 no.3
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• pp.224-228
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• 2017

Two specimens of Ruvettus pretiosus (227.0 and 238.3 mm in standard length), belonging to the family Gempylidae, was firstly collected by using a gill net from the eastern coastal waters of Jejudo Island, Korea in November 2013. This species is characterized by having the following morphological traits: XV, 17~19+2 dorsal fin rays; II, 15~16+2 anal fin rays; belly keeled between pelvic fin and anus; body covered with cycloid scales, interspaced with rows of sharp bony tubercles. R. pretiosus can be easily distinguished from three Korean Snake mackerels (Thyrsitoides marleyi, Rexea prometheoides and Gempylus serpens) by having belly keeled between pelvic fin and anus, and cycloid scales covered the body and interspaced with rows of sharp bony tubercles. Based on morphological and molecular approaches, the specimens were identified as R. pretiosus. We propose new Korean names, "Gi-reum-chi-sok" and "Gi-reum-chi" for the genus and species, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.10
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• pp.1089-1095
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• 2011

Numerical simulation is performed for nucleate boiling on a micro-finned surface, which has been widely used to enhance heat transfer, by solving the equations governing the conservation of mass, momentum, and energy in the liquid and vapor phases. The bubble motion is determined by a sharp-interface level-set method, which is modified to include the effect of phase change and to treat the no-slip and contact-angle conditions, as well as the evaporative heat flux from the liquid microlayer on immersed solid surfaces such as micro fins and cavities. The numerical results for bubble formation, growth, and departure on a microstructured surface including fins and cavities show that the bubble behavior during nucleate boiling is significantly influenced by the fin-cavity arrangement and the fin-fin spacing.

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.2116-2124
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• 2003

An experimental study providing additional knowledge of quasi-conical symmetry in swept shock wave/turbulent boundary-layer interactions is described. When a turbulent boundary layer on the flat plate is subjected to interact with a swept planar shock wave, the interaction flowfield far from fin leading edge has a nature of conical symmetry, which topological features of the interaction flow appear to emanate from a virtual conical origin. Surface streakline patterns obtained from the kerosene-lampblack tracings have been utilized to obtain representative surface features of the flow, including the location of the virtual conical origin. The scaling law for the sharp-fin interactions suggested by previous investigators has been reexamined for different freestream Mach numbers. It is noticed that the scaling law reasonably agrees with the present experimental data, however, that the law is not appropriate to estimate the location of the virtual conical origin. Further knowledge of the correlation for the virtual conical origin has thus been proposed.

• Korean Journal of Ichthyology
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• v.19 no.1
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• pp.70-72
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• 2007

A single specimen of the family Agonidae was collected from the coastal waters of the East Sea, Korea. It was identified as Hypsagonus corniger Taranetz by having the first dorsal fin with seven spines, long supraoccipital spine, sharp spines of body plate, no process on the supralateral bony plates, the broader distance between the first and the second dorsal fins than base of the second dorsal fin, and longer second spine of the first dorsal fin than the first spine. A key to the genus Hypsagonus from Korea is provided. We propose a new Korean name, "Ga-si-jul-go-gi" for the species.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.273-282
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• 2009

The taxonomic review of the family Trachipteridae was carried out based on the Trachipterus ishikawae (7 specimens), Zu cristatus (4 specimens), Desmodema polystictum (2 specimens) collected from the East Sea, South Sea and adjacent waters of Jeju Island of Korea from June 2006 to August 2008. Among them, D. polystictum was revealed as an unrecorded species from Korea, being characterized by the following characters: the ventral edge smooth; body color silvery white with a lot of large dark rounded spot. We proposed the new Korean name of the genus Desmodema as "Jeom-tu-ra-chi-sog", D. polystictum as "Jeom-tu-ra-chi". Z. cristatus has a elongated first six dorsal fin and pelvic fin rays. T. ishikawae has a row of sharp tubercles along the ventral edge, and straightly elongated body form. In meristic characters, the number of dorsal fin rays were 178~195 in T. ishikawae, 137~148 in Z. cristatus and 125~130 in D. polystictum, the number of vertebrae were well distinguished among three species; T. ishikawae (80~83), D. polystictum (72~74) and Z. cristatus (65~68).