• Title/Summary/Keyword: Rectangular annular fin

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Comparison of Heat Transfer Between 1-D and 2-D Analyses for a Rectangular Annular Fin (사각 환형 핀에 대한 1차원과 2차원 해석의 열전달 비교)

  • Kang, Hyung-Suk
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.1177-1181
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    • 2009
  • Heat loss from a convective rectangular profile annular fin with variable inside fluid heat transfer coefficient and fin height is calculated by using both the one dimensional analytic method and two dimensional variables separation method. Heat loss from the two dimensional method and the relative error of heat loss between the one dimensional method and two dimensional method are presented as a function of the fin length, ambient convection characteristic number and fin height. One of the results shows that the relative error of heat loss between one dimensional method and two dimensional method is within 0.7% in the range of given parameters in this study.

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Optimization of an Annular Fin with Variable Pipe Inside Radius in the Heat Exchanger of Ground Source System (지열시스템의 열교환기에서 원 관 내부 반경이 변하는 환형 핀의 최적화)

  • Kang, Hyung-Suk
    • New & Renewable Energy
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    • v.5 no.1
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    • pp.40-46
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    • 2009
  • Optimization of a rectangular profile annular fin with variable pipe inside radius is presented. This optimum procedure is based on fixed fin height and is made by using variables separation method. The optimum heat loss, corresponding optimum fin length and optimum fin efficiency are presented as a function of pipe inside radius, fin half height, inside fluid convection characteristic number and ambient convection characteristic number. One of results shows that the optimum fin length increases linearly with increase of pipe inside radius for fixed fin height and fin base radius.

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Optimization of a Convective Rectangular Profile Annular Fin (대류 직각 형상 환형 휜의 최적화)

  • 강형석;조철현
    • Journal of the Korean Society of Propulsion Engineers
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    • v.7 no.1
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    • pp.1-9
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    • 2003
  • The rectangular profile annular fin with fixed volume is optimized using 2-dimensional analytic method. For a base boundary condition, convection from fluid within the pipe to the inside wall of the pipe and conduction from the inside wall of the pipe to the fin base are considered. Heat loss from the fin tip radius is not ignored. The maximum heat loss, the optimum fin tip radius and the optimum fin half thickness corresponding to the maximum heat loss are presented as a function of fin base radius, Biot number over the fin surface and Biot number within the pipe. Results show 1) the maximum heat loss increases as both Biot number over the fin surface and Biot number within the pipe increase and as fin base radius decreases 2) the optimum fin thickness increases as Biot number within the pipe decreases or as fin base radius and Biot number over the fin surface increase.

Analysis of the Transient Response in Annular Fin with Rectangular Profile (구형단면을 갖는 환상휜에서의 과도응답 해석)

  • Kim Kwang Soo;Yong Ho Taek
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.16 no.5
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    • pp.504-515
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    • 1987
  • This study conducts an analysis for the heat diffusion of an annular fin considering con-vection phenomena at the fin edge as well as along the fin perimeter. When the temperature of the fin base is given with an increasing exponential function, the exact series solutions of tem-perature distribution are obtained by laplace transformation in terms of dimensionless para-meters. From these solutions heat flux and fin efficiency can be obtained. These exact solu-tions converge rapidly for large values of dimensionless time, but slowly for small ones. To avoid this convergence difficulty, approximate solutions of the temperature distribution and heat flux for small values of dimensionless time are also presented. Substituting the variations of dimensionless parameters into the these exact solutions, the characteristics of these response are investigated.

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Optimization of an Annular Fin with a Pipe of Variable Inner Radius for Fixed Fin Volume (고정된 휜 체적에 기준한 원관 내부반경이 변하는 환형 휜의 최적화)

  • Kang, Hyung-Suk
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.3
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    • pp.229-235
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    • 2010
  • Optimum values of fin performance and dimensions for an annular fin with a rectangular profile and a pipe with variable inner radius are determined by using a variable separation method. The range of ambient convection characteristic number that results in optimum heat loss is listed. The optimum heat loss, corresponding optimum fin effectiveness, fin length, and fin height are presented as a function of the inner radius of the pipe, inner fluid convection characteristic number, fin volume, and ambient convection characteristic number. One of the results shows that the optimum heat loss, fin effectiveness and fin length increase linearly with the inner radius of the pipe when both the fin volume and fin-base radius are fixed.

Counter-Current Gas-Liquid Two-Phase Flow in Narrow Rectangular Channels with Offset Strip Fins (휜이 있는 협소 사각 유로에서 대향류 기/액 2상 유동)

  • Sohn, B.H.;Kim, B.J.;Jeong, S.
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.229-234
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    • 2001
  • An adiabatic counter-current vertical two-phase flow of air and water in narrow rectangular channels with offset strip fm was investigated experimentally. Tests were systematically performed with downward liquid superficial velocities and upward gas velocities covering 0 to 0.06 m/s and 0 to 2.5 m/s ranges, respectively. Two-phase flow regimes were classified by examining the video images of flow patterns in transparent test sections of 760 mm long and 100 mm wide channel with gaps of 3.0 and 5.0 mm. The channel average void fraction was measured by the quick-closing valve method. Unlike the flow regimes in the channels without fin, where bubbly, slug, chum, and annular flow were identified, only bubbly and chum flow regimes were found for the channels with offset strip fin. However the existence of fin in the channels showed negligible effects on the void fraction. Instead counter-current flow limitations were found to happen at lower air superficial velocity once offset strip fin was introduced in narrow rectangular channels.

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