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Full-coverage film cooling. Part 1. Three-dimensional measurements of turbulence structure

Published online by Cambridge University Press:  19 April 2006

S. Yavuzkurt ,
R. J. Moffat  and
W. M. Kays
S. Yavuzkurt
Affiliation:
Mechanical Engineering Department, Stanford University, CA 94305
R. J. Moffat
Affiliation:
Mechanical Engineering Department, Stanford University, CA 94305
W. M. Kays
Affiliation:
Mechanical Engineering Department, Stanford University, CA 94305
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Abstract

Hydrodynamic measurements were made with a triaxial hot wire in the full-coverage region and the recovery region following an array of injection holes inclined downstream, at 30° to the surface. The data were taken under isothermal conditions at ambient temperature and pressure for two blowing ratios: M = 0·9 and M = 0·4. (The ratio M = ρjetUjet/ρ∞U∞, where U is the mean velocity and ρ is the density. Subscripts jet and ∞ stand for injectant and free stream, respectively.) Profiles of the three mean-velocity components and the six Reynolds stresses were obtained at several spanwise positions at each of five locations down the test plate.

In the full-coverage region, high levels of turbulence kinetic energy (TKE) were found for low blowing and low TKE levels for high blowing. This observation is especially significant when coupled with the fact that the heat transfer coefficient is high for high blowing, and low for low blowing. This apparent paradox can be resolved by the hypothesis that entrainment of the mainstream fluid must be more important than turbulent mixing in determining the heat transfer behaviour at high blowing ratios (close to unity).

In the recovery region, the flow can be described in terms of a two-layer model: an outer boundary layer and a two-dimensional inner boundary layer. The inner layer governs the heat transfer.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 101 , Issue 1 , 13 November 1980 , pp. 129 - 158
Copyright
© 1980 Cambridge University Press

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References

Bergeles, G., Gosman, A. D. & Launder, B. E. 1975 The prediction of three-dimensional discrete-hole cooling processes. I. Laminar flow. A.S.M.E. paper 75-WA/HT-109.Google Scholar
Brunner, M. S. 1969 Active cooling heat protection. J. Space Craft 6, no. 6.Google Scholar
Choe, H., Kays, W. M. & Moffat, R. J. 1975 Turbulent boundary layer on a full-coverage film-cooled surface. An experimental heat transfer study with normal injection. N.A.S.A. Rep. CR-2642. (Also Stanford Univ., Mech. Engng Dept Rep. HMT-22.)Google Scholar
Colladay, R. S. & Russell, L. M. 1975 Flow visualization of discrete-hole film cooling for gas turbine applications. N.A.S.A. Rep. TM X-71766.Google Scholar
Crawford, M. E. & Kays, W. M. 1975 STAN5 - A program for numerical computation of two-dimensional internal/external boundary-layer flows. Stanford Univ., Mech. Engng Dept Rep. HMT-23.Google Scholar
Crawford, M. E., Kays, W. M. & Moffat R. J. 1976 Heat transfer to a full-coverage film-cooled surface with 30-deg. slant-hole injection. Stanford Univ., Mech. Engng Dept Rep. HMT-25.Google Scholar
Escudier, M. P. 1966 The distribution of mixing-length in turbulent flows near walls. Imperial College, Heat Transfer Section Rep. TWF/TN/1.Google Scholar
Foster, R. C. & Haji-Sheikh, A. 1974 An experimental investigation of boundary layer heat transfer in the region of separated flow downstream of normal injection slots. A.S.M.E. Paper 74-HT-12.Google Scholar
Goldstein, R. J. 1971 Film cooling. Adv. Heat Transfer 7, 269–321.Google Scholar
Hartnett, J. P., Birkebak, R. C. & Eckert, E. R. G. 1961 Velocity distributions, temperature distributions, effectiveness, and heat transfer for air injected through a tangential slot into a turbulent boundary layer. Trans. A.S.M.E. C, J. Heat Transfer 83, 293–306.Google Scholar
Hinze, J. O. 1975 Turbulence, 2nd edn, p. 643. McGraw-Hill.
Kacker, S. C. & Whitelaw, J. H. 1970 Prediction of wall-jet and wall-wake flows. J. Mech. Engng Sci. 12 (6), 404–420.Google Scholar
Klebanoff, P. S. 1955 Characteristics of turbulence in a boundary layer with zero pressure gradient. N.A.C.A. Tech. note 1247.Google Scholar
Launder, B. E. & York, J. 1974 Discrete-hole cooling in the presence of free-stream turbulence and strong favorable pressure gradient. Int. J. Heat Mass Transfer 17, 1403–1409.Google Scholar
Le Brocq, P. V., Launder, B. E. & Priddin, C. H. 1971 Discrete-hole injection as a means of transpiration cooling - An experimental study. Imperial College Rep. HTS/71/37.Google Scholar
Mayle, R. E. & Camarata, F. J. 1975 Multihole cooling film-effectiveness and heat transfer. Trans. A.S.M.E. C, J. Heat Transfer 97, 534–538.Google Scholar
Metzger, D. E., Carper, H. J. & Warren, J. M. 1972 Predicted film cooling near flush slots - Comparison with experiment. J. Aircraft 9, 857–863.Google Scholar
Metzger, D. E., Takeuchi, D. I. & Kuenstler, P. A. 1973 Effectiveness and heat transfer with full-coverage film-cooling. J. Engng Power 95, 180–184.Google Scholar
Nina, M. N. R. & Whitelaw, J. H. 1971 The effectiveness of film cooling with three-dimensional slot geometry. Gas Turbine Conference and Products Show, Houston, Texas. A.S.M.E. Paper no. 71-GT-11.Google Scholar
Prandtl, L. 1925 Über die ausgebildete Turbulenz. Z. angew. Math. Mech. 5, 136–139; and Proc. 2nd Intern. Congr. Applied Mech., Zurich, 1926, pp. 62–75; also Coll. Works II, 736–751.Google Scholar
Ramsey, J. W. & Goldstein, R. J. 1971 Interaction of a heated jet with a deflecting stream. Trans. A.S.M.E. C, J. Heat Transfer 93, 365–372.Google Scholar
Samuel, A. E. & Joubert, P. N. 1965 Film cooling of an adiabatic flat plate in zero pressure gradient in the presence of a hot mainstream and cold tangential secondary injection. Trans. A.S.M.E. C, J. Heat Transfer 87, 409–419.Google Scholar
Schlichting, H. 1968 Boundary-Layer Theory, 6th edn, p. 533. McGraw-Hill.
Seban, R. A. & Back, L. H. 1962 Velocity and temperature profiles in turbulent boundary layers with tangential injection. Trans. A.S.M.E. C, J. Heat Transfer 84, 45–54.Google Scholar
Yavuzkurt, S., Moffat, R. J. & Kays, W. 1977a Full-coverage film cooling: three-dimensional measurements of turbulence structure and prediction of recovery region hydrodynamics. Stanford Univ., Mech. Engng Dept Rep. HMT-27.Google Scholar
Yavuzkurt, S., Moffat, R. J. & Crawford, M. E, 1977b Real-time hot-wire measurements in three-dimensional flows. Proc. 5th Biennial Symp. on Turbulence.Google Scholar