한국산학기술학회논문지 (Journal of the Korea Academia-Industrial cooperation Society)

  • 제12권9호
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  • Pages.3808-3814
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  • 2011
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  • 1975-4701(pISSN)
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  • 2288-4688(eISSN)
한국산학기술학회 (The Korea Academia-Industrial cooperation Society)
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삼각형 단면 덕트 내의 Shear-Thinning 유체에 대한 열전달 촉진에 관한 연구

A Study on Heat Transfer Enhancement for a Shear-Thinning Fluid in Triangular Ducts

  • 이동렬 (대구가톨릭대학교 기계자동차공학부)
  • Lee, Dong-Ryul (School of Mechanical and Automotive Engineering, Catholic University of Daegu)
  • 투고 : 2011.07.04
  • 심사 : 2011.09.08
  • 발행 : 2011.09.30
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초록

본 연구는 열교환기의 효율적인 설계를 위하여 열교환기 내의 삼각형 단면 덕트의 비뉴톤 유체의 압력강하 및 대류 열전달률 수치해석적으로 수행하였다. 비뉴톤 유체의 구성방정식은 기존의 비뉴톤 유체 멱법칙을 보완한 수정 멱법칙 모델을 채택하였다. 덕트 내의 압력강하를 의미하는 마찰계수와 수정 레이놀즈 수의 곱은 기존 연구의 문헌치와 비교할 때 뉴톤 유체 영역과 비뉴톤 멱법칙 영역에서 각각 0.13% 및 2.85% 내에서 일치함을 보였고 비뉴톤 수정멱법칙 유체 모델의 형태를 띠는 Shear-Thinning 유체를 열교환기 내의 삼각형 단면 덕트 내에서 사용하면 뉴톤 유체보다 62%의 압력강하를 감소시켰고 12%의 대류 열전달 향상을 발생시킬 수 있었다.

The prediction of heat transfer and pressure drops in the exchanger passages is a clue to the problem of heat exchanger design. In order to make such predictions for non-Newtonian fluids, it is necessary to know the relation between the viscous properties of the fluid and the wall shear rate in the duct. This study deals with the limits of validity of the power law equation. The useful methodology of the present research involves a consideration of a more general equation which has power law and Newtonian behavior as asymptotes. It isconcluded that use of the power law equation outside of its applicability range can lead to serious errors inpredicting the heat transfer and pressure drops. The present computational results of the friction factors times Reynolds number for shear-thinning fluid flows in a triangular duct are compared with previous published results, showing agreement with 0.13 % in Newtonian region and 2.85 % in power law region. These shear-thinning fluid results also showed the 12% increase of convective heat transfer enhancement compared with Newtonian heat transfer.

키워드

참고문헌

  1. Shah, R. K.and London, A. L., "Laminar Flow Forced Convection in ducts, Supplement 1 to Advances in Heat Transfer, pp. 227-231. (T. F. Irvine,Jr, and J. P. Hartnett, ed.)", Academic Press, New York, 1978.
  2. Sparrow, E. M., "Laminar Flow in Isosceles Triangular ducts", AIChE J., Vol. 8, pp. 599-605, 1962. https://doi.org/10.1002/aic.690080507
  3. Migay, V. K., "Hydraulic Resistance of Triangular Channels in Laminar Flow", Energy, Vol. 6, No. 5, pp. 122-130, 1963.
  4. Eckert, E. R. G. and Irvine, T. F. Jr, "Pressure Drop and Heat Transfer in a duct with Triangular Cross Section", J. Heat Transfer, Vol. 82, pp. 125-132, 1960. https://doi.org/10.1115/1.3679891
  5. Kozicki, W. C., Chou, H. and Tiu, C. "Non-Newtonian Flow in ducts of Arbitrary Cross-Sectional Shape", Chemical Engineering Science, Vol. 21, pp. 665-669, 1966. https://doi.org/10.1016/0009-2509(66)80016-7
  6. J. A. Cheng, "Laminar Forced Convective Heat Transfer of Power Law Fluids in Isosceles ducts with Peripheral Wall Condition", Ph.D. Thesis, Mechanical Eng.Dept., State Univ. of New York, 1985.
  7. Sutterby, J. L. "Laminar Converging Flow of Dilute Polymer Solution in Conical Section-I. Viscosity Data, New Viscosity Model, Tube Flow Solution", AIChE J., Vol. 12, pp. 63-77, 1966. https://doi.org/10.1002/aic.690120114
  8. Cross, M. M., "Rheology of Non-Newtonian Fluids: A New Equation for Pseudoplastic Systems", J. Colloid. Sci., Vol. 20, pp. 417-428, 1965. https://doi.org/10.1016/0095-8522(65)90022-X
  9. Carreau, P. J., "Rheological Equations from Molecular Network Theory", Tran.Soc.Rheol., Vol. 16, pp. 99-110, 1972. https://doi.org/10.1122/1.549276
  10. Dunleavy, J. E. and Middleman, S., "Relation of Shear Behavior of Solution of Polyisobutylene", Tran.Soc.Rheol., Vol. 10, pp. 151-164, 1966.
  11. Chang, J. A. "Laminar Forced Convective Heat Transfer of Power Law Fluids in Isosceles ducts with Peripheral Wall Condition", Ph.D. Thesis, Mechanical Eng.Dept., State Univ. of New York, 1985.