The endwall film-cooling cooling configuration investigated by Friedrichs et al. (1996, 1997) had in principle sufficient cooling flow for the endwall, but in practice, the redistribution of this coolant by secondary flows left large endwall areas uncooled. This paper describes the attempt to improve upon this datum cooling configuration by redistributing the available coolant to provide a better coolant coverage on the endwall surface, while keeping the associated aerodynamic losses small. The design of the new, improved cooling configuration was based on the understanding of endwall film-cooling described by Friedrichs et al. (1996, 1997). Computational fluid dynamics were used to predict the basic flow and pressure field without coolant ejection. Using this as a basis, the above-described understanding was used to place cooling holes so that they would provide the necessary cooling coverage at minimal aerodynamic penalty. The simple analytical modeling developed by Friedrichs et al. (1997) was then used to check that the coolant consumption and the increase in aerodynamic loss lay within the limits of the design goal. The improved cooling configuration was tested experimentally in a large-scale, low-speed linear cascade. An analysis of the results shows that the redesign of the cooling configuration has been successful in achieving an improved coolant coverage with lower aerodynamic losses, while using the same amount of coolant as in the datum cooling configuration. The improved cooling configuration has reconfirmed conclusions from Friedrichs et al. (1996, 1997): First, coolant ejection downstream of the three-dimensional separation lines on the endwall does not change the secondary flow structures; second, placement of holes in regions of high static pressure helps reduce the aerodynamic penalties of platform coolant ejection; finally, taking account of secondary flow can improve the design of endwall film-cooling configurations.

1.
Bario
F.
,
Leboeuf
F.
,
Onvani
A.
, and
Seddini
A.
,
1990
, “
Aerodynamics of Cooling Jets Introduced in the Secondary Flow of a Low-Speed Turbine Cascade
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
112
, pp.
539
546
.
2.
Blair
M. F.
,
1974
, “
An Experimental Study of Heat Transfer and Film Cooling on Large-Scale Turbine Endwalls
,”
ASME Journal of Heat Transfer
, Vol.
96
, pp.
524
529
.
3.
Bourguignon, A. E., 1985, “Etudes des Transferts Thermiques sur les Plates-Formes de Distributeur de Turbine avec et sans Film de Refroidissement,” AGARD-CP-390, Heat Transfer and Cooling in Gas Turbines.
4.
Dawes, W. N., 1988, “A Computer Program for the Analysis of Three Dimensional Viscous Compressible Flow in Turbomachinery Blade Rows,” Whittle Laboratory, University of Cambridge.
5.
Friedrichs
S.
,
Hodson
H. P.
, and
Dawes
W. N.
,
1996
, “
Distribution of Film-Cooling Effectiveness on a Turbine Endwall Measured Using the Ammonia and Diazo Technique
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
118
, pp.
613
621
.
6.
Friedrichs
S.
,
Hodson
H. P.
, and
Dawes
W. N.
,
1997
, “
Aerodynamic Aspects of Endwall Film-Cooling
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
119
, pp.
786
793
.
7.
Goldman, L. J., and McLallin, K. L., 1977, “Effect of Endwall Cooling on Secondary Flows in Turbine Stator Vanes,” AGARD-CPP-214.
8.
Granser, D., and Schulenberg, T., 1990, “Prediction and Measurement of Film Cooling Effectiveness for a First-Stage Turbine Vane Shroud,” ASME Paper No. 90-GT-95.
9.
Harasgama
S. P.
, and
Burton
C. D.
,
1992
, “
Film Cooling Research on the Endwall of a Turbine Nozzle Guide Vane in a Short Duration Annular Cascade: Part 1—Experimental Technique and Results
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
114
, pp.
734
740
.
1.
Harrison, S., 1989, “The Influence of Blade Stacking on Turbine Losses,” Ph.D. Thesis, University of Cambridge;
2.
see also
Harrison
S.
,
1990
, “
Secondary Loss Generation in a Linear Cascade of High-Turning Turbine Blades
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
112
, pp.
618
624
.
1.
Jabbari, M. Y., Marston, K. C., Eckert, E. R. G., and Goldstein, R. J., 1996, “Film Cooling of the Gas Turbine Endwall by Discrete-Hole Injection,” ASME Journal of Turbomachinery, Vol. 118, No. 2.
2.
Sieverding
C. H.
,
1984
, “
Recent Progress in the Understanding of Basic Aspects of Secondary Flows in Turbine Blade Passages
,”
ASME Journal of Engineering for Gas Turbines and Power
, Vol.
107
, pp.
248
257
.
3.
Sieverding, C. H., and Wilputte, P., 1981, “Influence of Mach Number and Endwall Cooling on Secondary Flows in a Straight Nozzle Cascade,” ASME Journal of Engineering for Gas Turbines and Power, Vol. 113, No. 2.
4.
Takeishi
K.
,
Matsuura
M.
,
Aoki
S.
, and
Sato
T.
,
1990
, “
An Experimental Study of Heat Transfer and Film Cooling on Low Aspect Ratio Turbine Nozzles
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
112
, pp.
488
496
.
This content is only available via PDF.
You do not currently have access to this content.