The Applicability of the Perfect Contact Assumption

  • Madassar Manzoor
Chapter
Part of the Lecture Notes in Engineering book series (LNENG, volume 5)

Abstract

The heat flow within finned surfaces is conventionally analysed on the basis that there is perfect contact between the fins and the supporting surface. However, if the fins are not an integral part of the supporting surface then the inevitable roughness of the contacting surfaces prevents contact except at discrete zones across the contact interface. In this study a simplified model of the contact interface is developed in order to investigate the applicability of the perfect contact approximation. A multi-dimensional analysis is employed in order to accurately model the heat flow and solutions are computed employing a boundary integral equation method. The results obtained indicate that it is unnecessary to consider more sophisticated representations of the contact interface.

Keywords

Heat Transfer Heat Exchanger Heat Flow Contact Zone Heat Transfer Rate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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References

  1. 1.
    Sparrow, E.M. and Lee, L., “Effects of fin-base temperature depression in a multifin array”, Journal of Heat Transfer, Vol. 97, 1975, pp. 463–465.CrossRefADSGoogle Scholar
  2. 2.
    Suryanarayana, N.V., “Two-dimensional effects on heat transfer rates from an array of straight fins”, Journal of Heat Transfer, Vol. 99, 1977, pp. 129–132.CrossRefGoogle Scholar
  3. 3.
    Gardner, K.A. and Camovos, T.C., “Thermal contact resistance in finned tubing”, Journal of Heat Transfer, Vol. 82, 1960, pp. 279–293.Google Scholar
  4. 4.
    Young, E.H. and Briggs, D.E., “Bond resistance of bi-metallic finned tubes,” Chemical Engineering Progress, Vol. 61, 1965, pp. 71–84.Google Scholar
  5. 5.
    Kulhami, M.V. and Young, E.H., “Bi-metallic finned tubes”, Chemical Engineering Progress, Vol. 62, 1966, pp. 69–73.Google Scholar
  6. 6.
    Williams, A., “Heat flow across stacks of steel laminations”, Journal of Mechanical Engineering Science, Vol. 13, 1971, pp. 217–223.CrossRefGoogle Scholar
  7. 7.
    Thomas, T.R. and Probert, S.D., “Correlations for thermal contact conductance in vacua”, Journal of Heat Transfer, Vol. 94, 1972, pp. 276–281CrossRefGoogle Scholar
  8. 8.
    Madhusudana, C.V., “The effect of interface fluid on thermal contact conductance”, International Journal of Heat and Mass Transfer, Vol. 18, 1975, pp. 989–991.CrossRefGoogle Scholar
  9. 9.
    O’Callaghan, P.W., Jones, A.M. and Probert, S.D., “Effect of thermal contact resistance on the performance of transfomer lamination stacks”, Applied Energy, Vol. 3, 1977, pp.13–22.CrossRefGoogle Scholar
  10. 10.
    Edmonds, M.J., Jones, A.M., O’Callaghan, P.W. and Probert, S.D., “The prediction and measurement of thermal contact resistance”, Wear, Vol. 50, 1978, pp. 299–319.CrossRefGoogle Scholar
  11. 11.
    Barber, J.R., “The effect of thermal distortion on constriction resistance”, International Journal of Heat and Mass Transfer, Vol. 14, 1971, pp. 751–766.CrossRefGoogle Scholar
  12. 12.
    Mikic, B.B., “Thermal contact conductance: Theoretical considerations. International Journal of Heat and Mass Transfer”, Vol. 17, 1974, pp. 205–214.CrossRefGoogle Scholar
  13. 13.
    Gardner, K.A., “Efficiency of extended surface”, Transactions of the ASME, Vol. 67, 1945, pp. 621–631.Google Scholar
  14. 14.
    Mikk, I., “Convective fin of minimum mass”, International Journal of Heat and Mass Transfer, Vol. 23, 1980, pp. 707–711.CrossRefMATHGoogle Scholar
  15. 15.
    Smith, G.D., Numerical solution of partial differential equations, Oxford University Press, 1974.Google Scholar
  16. 16.
    Zienkiewicz, O.C., The finite element method in engineering, McGraw-Hill, London, 1971.MATHGoogle Scholar
  17. 17.
    Jaswon, M.A. and Symm, G.T., Integral equation methods in potential theory and electrostatics, Academic Press, London, 1977.Google Scholar
  18. 18.
    Heggs, P.J., Ingham, D.B. and Manzoor, M., “The analysis of fin assembly heat transfer by a series truncation method”, accepted for publication in Journal of Heat Transfer, 1981.Google Scholar
  19. 1.
    I. Mikk, “Convective fin of minimum mass”, International Journal of Heat and Mass Transfer, Vol. 23, pp. 707–711, 1980.CrossRefMATHGoogle Scholar
  20. 2.
    P.J. Heggs and P.R. Stones, “The effects of dimensions on the heat flow rate through Extended surfaces”, Journal of Heat Transfer, Vol. 102, pp. 180–182, 1980.CrossRefGoogle Scholar
  21. 3.
    Gardner, K.A. and Carnovos, T.C., “Thermal contact resistance in finned tubing”, Journal of Heat Transfer, Vol. 82, 1960, pp. 279–293.Google Scholar
  22. 4.
    Young, E.H. and Briggs, D.E., “Bond resistance of bi-metallic finned tubes”, Chemical Engineering Progress, Vol. 61, 1965, pp. 71–84.Google Scholar
  23. 5.
    Kulkarni, M.V. and Young, E.H., “Bi-metallic finned tubes”, Chemical Engineering Progress, Vol. 62, 1966, pp. 69–73.Google Scholar
  24. 6.
    B.B. Mikic, “Thermal contact conductance: theoretical considerations”, International Journal of Heat and Mass Transfer, Vol. 17, pp. 205–214, 1974.CrossRefGoogle Scholar
  25. 7.
    C.V. Madhusudana, “The effect of interface fluid on thermal contact conductances”, International Journal of Heat and Mass Transfer, Vol. 18, pp. 989–991, 1975.CrossRefGoogle Scholar
  26. 8.
    P.J. Heggs, D.B. Ingham and M. Manzoor, “The effects of thermal contact resistance on the performance of finned heat exchangers”, To be presented at the Second National Symposium on Numerical Methods in Heat Transfer, University of Maryland, USA, September 1981.Google Scholar
  27. 9.
    R.P. Forslund, “An experimental technique for determining the diffusion effect of braze material on the thermal conductance of thin copper fins”, Journal of Heat Transfer, Vol. 25, pp. 273–275, 1972.CrossRefGoogle Scholar
  28. 10.
    P.W. O’Callaghan, A.M. Jones and S.D. Probert, “Research Note: The thermal behaviour of gauzes as interfacial inserts between solids”, Journal of Mechanical Engineering Science, Vol. 17, pp. 233–236, 1975.CrossRefGoogle Scholar
  29. 11.
    F.R. Al-Astrabadi, P.W. O’Callaghan, A.M. Jones and S.D. Probert, “Thermal resistance resulting from commonly used inserts between stainless steel static bearing surfaces”, Wear, Vol. 40, pp. 339– 350, 1976.CrossRefGoogle Scholar
  30. 12.
    F.R. Al-Astrabadi, S.D. Probert, P.N. O’Callaghan and A.M. Jones, “Reduction of energy dissipation at thermally distorted pressed contacts”, Applied Energy, Vol. 5, pp. 23–51, 1979.CrossRefGoogle Scholar
  31. 13.
    E.M. Sparrow and L. Lee, “Effects of fin-base temperature depression in a multifin array”, Journal of Heat Transfer, Vol. 197, pp. 463–465, 1975.CrossRefADSGoogle Scholar
  32. 14.
    N.V. Suryanarayana, “Two-dimensional effects on heat transfer rates from an array of straight fins”, Journal of Heat Transfer, Vol. 99, pp. 129–132, 1977.CrossRefGoogle Scholar
  33. 15.
    G.D. Smith, Numerical Solution of Partial Differential Equations, Oxford University Press, 1974.Google Scholar
  34. 16.
    O.C. Zienkiewicz, The Finite Element Method in Engineering, McGraw-Hill, London 1971.MATHGoogle Scholar
  35. 17.
    M.A. Jaswon and G.T. Symm, Integral Equation Methods in Potential Theory and Electrostatics, Academic Press, London, 1977.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1984

Authors and Affiliations

  • Madassar Manzoor
    • 1
  1. 1.Dept. of Mathematical SciencesUniversity of DurhamDurhamEngland

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