• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.341-346
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• 2009

The purpose of the present study is to investigate the flow resistance and the heat transfer characteristics of oval fin-tube heat exchanger. Six kinds of oval fin having the same fin area and the different diameter ratio tested numerically. Test data for the heat transfer, pressure drop and fin temperature were shown and discussed. The pressure drop and heat transfer increased for increasing the oval fin diameter ratio(diameter of span-wise direction to diameter of longitudinal diameter) up to 50% and 45% respectively.

• Journal of computational fluids engineering
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• v.15 no.2
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• pp.1-6
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• 2010

The purpose of the present study is to investigate the flow resistance and the heat transfer characteristics of oval fin-tube heat exchanger. Six kinds of oval fin having the same fin area and different diameter ratio tested numerically. Test data for the heat transfer, pressure drop and fin temperature were shown and discussed. The pressure drop and heat transfer increased for increasing the oval fin diameter ratio(diameter of span-wise direction to diameter of longitudinal diameter) up to 50% and 45% respectively.

• Clean Technology
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• v.14 no.4
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• pp.265-270
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• 2008

In this study, the flow and heat transfer of the aligned pin-fin array of the air cooling module for electronic packaging application were numerically analyzed with various fin shapes. The geometric cross-sectional shapes of pin-fins considered in this study were ellipse, wing and circle. The fins had same cross-sectional area and height, but they had different surface areas. As the results, the surface area, the heat transfer coefficient, and the heat transfer performance of pin-fins greatly depended on their shapes. Of the three types of pin-fins, the wing type pin-fin with suitable shape produced the best heat transfer performance. This result implies that the cooling capacity of the pin-fin cooler can be significantly enhanced only by the change of fin shape without increasing air flow-rate or fin density.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2023-2028
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• 2008

In present study, the flow field near the fin surface of plate fin - oval tube heat exchanger with delta wing vortex generator was numerically analyzed. As results, the well developed vortex behind delta wing was observed. These vortex can improve heat transfer fin surface behind delta wing vortex generators.

• Korean Journal of Heritage: History & Science
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• v.53 no.3
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• pp.142-163
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• 2020

In the early Joseon dynasty, the meritorious vassals' portrait of Jeokgae (1467, 1476), Jeongguk (1506)·Jeongnan (1507), and Wisa (1545) were defined as the 2^nd period of the official uniform, in which the acheongsaek HeukDanryung appeared and settled. A total of seven portraits were analyzed, including three portraits of Jeokgae (1467, portrait production 1476) Son-so, Oh Jachi, and Jang Malson, and four portraits of Jeongguk (1506)·Jeongnan (1507) Yoo Sunjung, Hong Gyeongju, Lee Woo, and Yoo Hong. In the portrait of the Jeokgae wearing a Yebok HeukDanryung, in the case of the Samo, the height of the Samo, which had been raised at the beginning of King Seongjong, was lowered again, and the parietal part was rounded. The pattern was not expressed on the wide oval side wings of the Samo. In addition, the pattern was not expressed on the acheongsaek Danryung, Dapho, and Cheolrik. The colors of Dapho and Cheolrik were unified in green and red, respectively. The Mu of Danryung and Dapho was expressed as 'in and out wrinkled Mu', and the shoes were expressed in Baekhwa. Another feature is that the Jeokgae's portrait is expressed not as the Pumgye at the time of appointment, but as the Pumgye of the portrait production time. In the portrait of the Jeongguk·Jeongnan wearing a Sibok HeukDanryung, the height of the Samo lowered from the Jeokgae was maintained, while the parietal part was slightly narrowed and bent forward. The side wings of the Samo were expressed as an oval with a uniform width, and still the pattern was not expressed on the side wings. The pattern was not expressed in the costume of the Danghagwan's portrait, but the cloud pattern began to be expressed in the costume of the Dangsanggwan's portrait. And the Danryung was expressed as single Danryung without lining. In the portrait of Dangsang, the red Dapho and green Cheolrik were expressed, and in the portrait of Dangha, the green Dapho and blue Cheolrik were expressed. Therefore, it was found that the color of the undergarment was distinguished according to the Dangsang and Dangha. In Danryung and Dapho, the 'in and out wrinkled Mu' were maintained. The shoes were expressed in Heukhwa, and the rank badge and rank belt reflect the Pumgye at the time of the appointment. On the other hand, the portrait of Wisa could not be confirmed, but through the recording painting of the reign of King Meongjong, it was found that it was similar to the Danryung system of the reign of King Jungjong. Through the 2^nd period of the meritorious vassal's portrait of Jeokgae, it was confirmed that the HeukDanryung outfit began to be used as the official uniform of the meritorious vassal's portrait, and that the Pumgye of the portrait production time was reflected in the portrait. After the meritorious vassal's portrait of Jeongguk, the pattern began to be expressed in the costumes, and in particular, it was possible to distinguish Dasang and Dangha by the presence or absence of the HeukDanryung's pattern. In addition, it was confirmed that the expressed aspect of the official uniform was consistent with the practices and regulations at the time.