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A Study on the Heat Transfer Characteristics of Turbulent Round Jet Impinge on the Inclined Concave Surface Using Transient Liquid Crystal Method

과도액정 기법을 이용한 오목표면 경사각도에 따른 난류 충돌 제트의 열전달 특성에 관한 연구

  • 임경빈 (한밭대학교 기계공학과) ;
  • 이창희 (한양대학교 기계공학과) ;
  • 이상훈 (한밭대학교 대학원 기계공학과)
  • Published : 2006.07.01

Abstract

The effects of concave hemispherical surface with inclined angle on the local heat transfer from a turbulent round jet impinging were experimentally investigated using transient liquid crystal method. This method suddenly exposes a preheated wall to an impinging jet and then the video system records the response of liquid crystals for the measurement of the surface temperature. The Reynolds numbers were used 11000, 23000 and 50000, nozzle-to-surface distance ratio from 2 to 10 and the surface angles $\alpha=0^{\circ},\;15^{\circ},\;30^{\circ}\;and\;40^{\circ}$. Correlations of the stagnation point Nusselt number according to Reynolds number, jet-to-surface distance ratio and dimensionless surface angle are investigated. In the stagnation point, in term of $Re^n$, n ranges from 0.43 in case of $2{\leq}L/d\leq6$ to 0.45 in case of $6. The maximum Nusselt number occurs in the direction of upstream. The displacement of the maximum Nusselt number from the stagnation point increases with increasing surface angle or decreasing nozzle-to-surface distance. The maximum displacement is about 0.7 times of the jet nozzle diameter.

Keywords

References

  1. Gardon, R. and Cobonpue, J., 1962, 'Heat Transfer Between a Flat Plate and Jets of Air Impinging on It,' International Development in Heat Transfer, ASME, pp. 454-460
  2. Gardon, R. and Akfirat, J.C., 1965,. 'The Role of Turbulence in Determining the Heat Transfer Characteristics of Impinging Jets,' International Journal of Heat and Mass Transfer, Vol. 8, pp. 1261-1272 https://doi.org/10.1016/0017-9310(65)90054-2
  3. Hrycak, P., Lee, D. T., Gauntner, J. W. and Livingood, J. N. B., 1970, 'Experimental Flow Characteristics of a Single Turbulent Jet Impinging on a Flat Plate,' NASA TN D-5690
  4. Martin, H., 1977, 'Heat and Mass Transfer Between Impinging Gas Jet and Solid Surfaces,' Advances in Heat Transfer, Vol. 13, pp. 1-60 https://doi.org/10.1016/S0065-2717(08)70221-1
  5. Goldstein, R.J. and Franchett, M.E., 1988, 'Heat Transfer from a Flat Surface to an Oblique Impinging Jet,' Journal of Heat Transfer, Vol. 110, pp. 84-90 https://doi.org/10.1115/1.3250477
  6. Lamont, P.L. and Hunt, B.L., 1980, 'The Impingement of Under expanded, Axi-symmetric Jets on Perpendicular and Inclined Flat Plates,' Journal of Fluid Mechanics, Vol. 100, Part 3, pp. 471-511 https://doi.org/10.1017/S0022112080001255
  7. Rubel, A., 1981, 'Computations of the Oblique Impingement of Round Jets upon a Plane Wall,' AIAA Journal, Vol. 19, pp. 863-871 https://doi.org/10.2514/3.7829
  8. Gau, C. and Chung, C.M., 1991, 'Surface Curvature Effect on Slot-Air Jet Impinging Cooling Flow and Heat Transfer Process,' ASME Journal of Heat Transfer, Vol. 113, pp. 858-864 https://doi.org/10.1115/1.2911214
  9. Yan, X., 1993, 'A Preheated-Wall Transient Method Using Liquid Crystals for the Measurement of Heat Transfer on External Surfaces and in Ducts,' Ph.D. Dissertation, University of California, Davis
  10. Lim, K.B., 1995, 'Measurement of the Heat Transfer Coefficent on a Concave Surface with a Turbulent Round Impinging Jet,' The Society of Airconditioning and Refrigerating Engineers of Korea Vol., No.1, pp. 112-119
  11. Yan, X., Baughn, J.W. and Mesbah, M., 1992, 'The Effect of Reynolds Number on the Heat Transfer Distribution from a Flat Plate to an Impinging Jet,' ASME HTD-Vol. 226, pp. 11-18
  12. Baughn, J.W. and Van, X., 1991, 'An Insertion Technique Using the Transient Method with Liquid Crystals for Heat Transfer Measurements in Ducts,' Fouling and Enhancement Interactions, Rabas, T.J. and Chenoweth, J.M., Edited, ASME HID-Vol. 164, pp. 77-83
  13. Vedula, R.P., Metzger, D.E. and Bickford, W.B., 1988, 'Effect of Lateral and Anisotropy Conduction on Determination of Local Convection Heat Transfer Characteristics with Transient Tests and Surface Coating,' ASME Collected Papers in Heat Transfer, HTD-Vol. 104, pp. 21-27
  14. Kline, S.J. and Mcklintock, F.A., 1953, 'Describing Uncertainties in Single Sample Experiments,' Mechanical 'Engineering, Vol. 75, No. 1, pp. 3-8
  15. Lim, K.B. and Lee, D.H., 1997, 'Concave Surface Curvature Effect on Heat Transfer from a Turbulent Round Impinging Jet,' Trans. of the KSME (B), Vol. 21. No. 5, pp. 691-699
  16. Yoon, S.H., Kim, M.K. and Lee, D.H., 1996, 'Turbulence Flow and Heat Transfer Characteristics of a Two-Dimensional Oblique Plate Impinging Jet,' KSME Int. J., Vol. 11, No. 4, pp. 476-483
  17. Lee, D.H., Chung, Y.S., Kim, D.S. and Lim, K.B., 1997, 'Heat Transfer and Flow Characteristics of a Circular Jet Impinging on a Convex Curved Surface,' Trans. of the KSME (B), Vol. 21, No. 4, pp. 579-588

Cited by

  1. Effect of Inclined Jet on Heat/Mass Transfer for Impingement/Effusion Cooling System vol.32, pp.4, 2008, https://doi.org/10.3795/KSME-B.2008.32.4.283