• Title/Summary/Keyword: Oval fin

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Local Heat Transfer Characteristics on Fin Surface of Plate Fin - Oval Tube with Delta Wing Vortex Generators (Plate fin-oval tube 열교환기에서 와류발생체에 의한 fin 표면에서의 국소 열전달 특성)

  • Shin, Seok-Won;Chung, In-Kee;Kim, Soo-Youn
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2390-2395
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    • 2007
  • The present research was experimentally performed to analyze the effect of delta-wing vortex generators(DWVG) on the heat transfer of fin surface of the plate fin-oval tube. The local heat transfer coefficient of the fin surface for four kinds of DWVG's arrangement was measured by the naphthalene sublimation technique for Reynolds numbers ranging from 2000 to 3200. The results showed that the heat transfer of the plate fin-oval tube can be significantly enhanced by DWVG for relatively low Reynolds numbers.

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CONVECTIVE HEAT TRANSFER CHARACTERISTICS OF OVAL FIN-CIRCULAR TUBE HEAT EXCHANGER (타원형휜-원형관 열교환기의 강제대류 열전달 특성)

  • Kang, H.C.;Lee, J.H.
    • 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.

CONVECTIVE HEAT TRANSFER CHARACTERISTICS OF OVAL FIN-CIRCULAR TUBE HEAT EXCHANGER (타원형휜-원형관 열교환기의 강제대류 열전달 특성)

  • Kang, H.C.;Lee, J.H.
    • 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.

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The Numerical Analysis of the Flow Fields near Fin Surface of a Plate Fin-Oval Tube Heat Exchanger with Delta Wing Vortex Generators (Delta Wing Vortex Generator가 부착된 Plate Fin-Oval Tube 열교환기에서 휜 주위의 유동에 대한 수치적 해석)

  • Shin, Seok-Won;Chung, In-Kee;Kim, Soo-Youn;Lee, Young-Woo
    • 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.

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Air-Side Performance of Fin-and-Tube Heat Exchangers Having Sine Wave Fins and Oval Tubes (사인 웨이브 핀과 타원관으로 구성된 핀-관 열교환기의 공기측 성능)

  • Choi, Byung-Nam;Yi, Fung;Sim, Hyun-Min;Kim, Nae-Hyun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.5
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    • pp.279-288
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    • 2013
  • Heat transfer and pressure drop characteristics of fin-and-tube heat exchangers having sine wave fins and oval tubes were investigated. Oval tubes having an aspect ratio of 0.6 were made, by deforming 12.7 mm round tubes. Twelve samples, having different fin pitch and tube row, were tested. The effect of fin pitch on the j and f factors was negligible. The effect of the tube row on the j factor, however, was different from that of common fin-and-tube heat exchangers having plain fins and round tubes. The highest j factor was obtained for a two-row configuration, while the lowest one was obtained for a one-row configuration. A possible reason was attributed to the flow mixing characteristics of the sine wave channel of the present geometry. Comparison with a plain fin-and-tube heat exchanger having 15.88 mm O. D. round tube reveals that the present oval fin-and-tube heat exchanger shows generally superior thermal performance, except for the one-row configuration.

Local Heat Transfer Characteristics on Fin Surface of Plate Fin-Oval Tube with Delta Wing Vortex Generators (Plate Fin-Oval Tube 열교환기에서 익형 와류발생체에 의한 Fin 표면에서의 국소 열전달에 대한 특성)

  • Shin, Seok-Won;Chung, In-Kee;Kim, Soo-Youn
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.10
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    • pp.757-766
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    • 2009
  • In the present study, the effect of delta-wing vortex generators(DWVG) on the local heat transfer of the plate fin-oval tube was experimentally analyzed for Reynolds numbers for 2000, 2500 and 3200. The local heat transfer coefficient of the fin surface for four type DWVGs was measured by the naphthalene sublimation technique. As the results, the distribution of the heat transfer coefficient at rear of DWVGs showed longitudinal contours for common flow down DWVGs and wavy contours for common flow up DWVGs. The distribution showed many cell type contours at near wall and downstream for all DWVGs. Compared to case without DWVGs in present experimental tests, all DWVGs showed the best enhancement of heat transfer at Re=2000. Of 4 cases of DWVGs, D type showed the best enhancement of heat transfer.

Wet Surface Air-Side Performance of Fin-and-Tube Heat Exchangers Having Sine Wave Fins and Oval Tubes (사인 웨이브 핀과 타원관으로 구성된 핀-관 열교환기의 공기측 습표면 성능)

  • Kim, Nae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2415-2423
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    • 2015
  • Experiments were conducted on sine wave fin-and-tube heat exchangers having oval tubes under wet condition. Oval tubes having an aspect ratio of 0.6 were made, by deforming 12.7mm round tubes. Twelve samples, having different fin pitch and tube row, were tested. Results showed that, for oval tube samples, the effect of fin pitch on j and f factor was not significant. As for the effect of tube row, the lowest j factor was obtained for one row configuration(81% of two row configuration), which is clear contrast to round tube samples, where the highest j factor was obtained for one row configuration. Possible reasoning is provided considering the flow and heat transfer characteristics of sine wave channel combined with connecting oval tubes. Comparison of $j/f^{1/3}$ with plain fin-and-tube heat exchanger having 15.9mm O.D. round tube reveals that present oval fin-and-tube heat exchanger shows superior thermal performance except for one row configuration. In other words, $j/f^{1/3}$ of the two row oval tube heat exchanger was 1.6~2.5 times larger than those of round tube heat exchanger, 1.4~2.4 times larger for three row configuration and 1.2~2.8 times for four row configuration.

Performance Characteristics of Fin-Tube Heat Exchanger having Large Diameter Oval Tube for Dryer (대구경 타원관을 적용한 건조기용 핀-관 열교환기의 성능특성)

  • Bae, Kyung-Jin;Cha, Dong-An;Kwon, Oh-Kyung
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.1
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    • pp.8-13
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    • 2015
  • The objective of this paper is to provide design data of fin-tube heat exchanger which have a large diameter oval tube for dryer application. In this study, the heat transfer and pressure drop performance characteristics of the fin-tube heat exchanger were compared with Dittus-Boelter and a new correlation equation using Wilson plot method. The simulation results based on section by section method were compared with experimental results. These results showed that a new correlation equation using Wilson plot method provided better prediction, about 3 to 12%, than the Dittus-Boelter equation, from the experiment comparison. Also, the pressure drop of simulation results showed much more deviation with the experimental results.

Heat Transfer Characteristics of Oval-Tube Heat Exchanger (타원관 열교환기의 열전달 특성)

  • 윤점열;이욱용
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.3
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    • pp.292-301
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    • 2000
  • This study experimentally investigates an air-side performance of oval tube heat exchanger against round tube heat exchanger using scaled-up model experiment for home air conditioners. A plain fin and round tube heat exchanger with 21 FPI(fins per inch) was used as a reference heat exchanger, and these were applied equally to 4 oval tube heat exchangers. Oval tube samples were designed with the same perimeter as 7.5mm diameter round tube, and their aspect ratios were 1:2, 1:3, respectively. In this study, the heat transfer and pressure drop characteristics of oval tube heat exchangers against round tube heat exchanger were also compared to one another, and an optimal samples for home air conditioners was recommended. And, general performance characteristics for an optimum oval tube samples chosen in this work was compared with round tube heat exchanger.

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