0
Research Papers

Effect of Internal Crossflow Velocity on Film Cooling Effectiveness—Part I: Axial Shaped Holes

[+] Author and Article Information
John W. McClintic

Department of Mechanical Engineering,
The University of Texas at Austin,
204 E. Dean Keeton Street,
Austin, TX 78712
e-mail: johnwmcclintic@gmail.com

Joshua B. Anderson

Department of Mechanical Engineering,
The University of Texas at Austin,
204 E. Dean Keeton Street,
Austin, TX 78712
e-mail: mranderson@utexas.edu

David G. Bogard

Department of Mechanical Engineering,
The University of Texas at Austin,
204 E. Dean Keeton Street,
Austin, TX 78712
e-mail: dbogard@mail.utexas.edu

Thomas E. Dyson

GE Global Research Center,
1 Research Circle,
Schenectady, NY 12309
e-mail: dyson@ge.com

Zachary D. Webster

GE Aviation,
1 Neumann Way,
Cincinnati, OH 45125
e-mail: Zachary.Webster@ge.com

1Corresponding author.

2Present address: Williams International, Commerce Charter Township, MI 48390.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received August 18, 2017; final manuscript received September 5, 2017; published online October 25, 2017. Editor: Kenneth Hall.

J. Turbomach 140(1), 011003 (Oct 25, 2017) (10 pages) Paper No: TURBO-17-1121; doi: 10.1115/1.4037997 History: Received August 18, 2017; Revised September 05, 2017

The effect of feeding shaped film cooling holes with an internal crossflow is not well understood. Previous studies have shown that internal crossflow reduces film cooling effectiveness from axial shaped holes, but little is known about the mechanisms governing this effect. It was recently shown that the crossflow-to-mainstream velocity ratio is important, but only a few of these crossflow velocity ratios have been studied. This effect is of concern because gas turbine blades typically feature internal passages that feed film cooling holes in this manner. In this study, film cooling effectiveness was measured for a single row of axial shaped cooling holes fed by an internal crossflow with crossflow-to-mainstream velocity ratio varying from 0.2 to 0.6 and jet-to-mainstream velocity ratios varying from 0.3 to 1.7. Experiments were conducted in a low speed flat plate facility at coolant-to-mainstream density ratios of 1.2 and 1.8. It was found that film cooling effectiveness was highly sensitive to crossflow velocity at higher injection rates while it was much less sensitive at lower injection rates. Analysis of the jet shape and lateral spreading found that certain jet characteristic parameters scale well with the crossflow-to-coolant jet velocity ratio, demonstrating that the crossflow effect is governed by how coolant enters the film cooling holes.

Copyright © 2018 by ASME
Your Session has timed out. Please sign back in to continue.

References

Schroeder, R. P. , and Thole, K. A. , 2014, “Adiabatic Effectiveness Measurements for a Baseline Shaped Film Cooling Hole,” ASME Paper No. GT2014-25992.
Anderson, J. B. , Boyd, E. J. , and Bogard, D. G. , 2015, “Experimental Investigation of Coolant-to-Mainstream Scaling Parameters With Cylindrical and Shaped Film Cooling Holes,” ASME Paper No. GT2015-43072.
Boyd, E. J. , McClintic, J. W. , Chavez, K. F. , and Bogard, D. G. , 2014, “Direct Measurement of Heat Transfer Coefficient Augmentation at Multiple Density Ratios,” ASME J. Turbomach., 139(1), p. 011005. [CrossRef]
Gritsch, M. , Schulz, A. , and Wittig, S. , 2003, “Effect of Internal Coolant Crossflow on the Effectiveness of Shaped Film-Cooling Holes,” ASME J. Turbomach., 125(3), pp. 547–554. [CrossRef]
Saumweber, C. , and Schulz, A. , 2008, “Comparison of the Cooling Performance of Cylindrical and Fan-Shaped Cooling Holes With Special Emphasis on the Effect of Internal Coolant Cross-Flow,” ASME Paper No. GT2008-51036.
Saumweber, C. , and Schulz, A. , 2012, “Effect of Geometry Variations on the Cooling Performance of Fan-Shaped Cooling Holes,” ASME J. Turbomach., 134(6), p. 061008. [CrossRef]
Kohli, A. , and Thole, K. A. , 1998, “Entrance Effects on Diffused Film-Cooling Holes,” ASME Paper No. 98-GT-402.
Gritsch, M. , Saumweber, C. , Schulz, A. , Wittig, S. , and Sharp, E. , 2000, “Effect of Internal Coolant Crossflow Orientation on the Discharge Coefficient of Shaped Film-Cooling Holes,” ASME J. Turbomach., 122(1), pp. 146–152. [CrossRef]
Wilkes, E. K. , Anderson, J. B. , McClintic, J. W. , and Bogard, D. G. , 2016, “An Investigation of Turbine Film Cooling Effectiveness With Shaped Holes and Internal Cross-Flow With Varying Operational Parameters,” ASME Paper No. GT2016-56162.
McClintic, J. W. , Anderson, J. B. , Bogard, D. G. , Dyson, T. E. , and Webster, Z. , 2017, “Effect of Internal Crossflow Velocity on Film Cooling Effectiveness—Part II: Compound Angle Shaped Holes,” ASME Paper No. Paper No. GT2017-64624.
Anderson, J. B. , Wilkes, E. K. , McClintic, J. W. , and Bogard, D. G. , 2016, “Effects of Freestream Mach Number, Reynolds Number, and Boundary Layer Thickness on Film Cooling Effectiveness of Shaped Holes,” ASME Paper No. GT2016-56152.
Klavetter, S. R. , McClintic, J. W. , Bogard, D. G. , Dees, J. E. , Laskowski, G. M. , and Briggs, R. , 2016, “The Effect of Rib Turbulators on Film Cooling Effectiveness of Round Compound Angle Holes Fed by an Internal Cross-Flow,” ASME J. Turbomach., 138(12), p. 121006. [CrossRef]
Dyson, T. E. , McClintic, J. W. , Bogard, D. G. , and Bradshaw, S. D. , 2013, “Adiabatic and Overall Effectiveness for a Fully Cooled Turbine Vane,” ASME Paper No. GT2013-94928.
Moffat, R. J. , 1985, “Using Uncertainty Analysis in the Planning of an Experiment,” ASME J. Fluids Eng., 107(2), pp. 173–178. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Schematic of test section and channel

Grahic Jump Location
Fig. 2

7-7-7 film cooling hole geometry

Grahic Jump Location
Fig. 3

Jet characteristic parameters—sample η profile at x/d = 10

Grahic Jump Location
Fig. 4

Test-to-test repeatability of laterally averaged effectiveness, DR = 1.2, VRc = 0.3

Grahic Jump Location
Fig. 7

Spatially averaged effectiveness, DR = 1.2, averaged from x/d = 5 to 20, plenum data from Ref. [2]

Grahic Jump Location
Fig. 8

Contours of uncorrected η at VR = 1.67 for VRc = 0.2, 0.4, and 0.6

Grahic Jump Location
Fig. 5

Laterally averaged effectiveness for selected streamwise location scaled with VR and M

Grahic Jump Location
Fig. 6

Laterally averaged effectiveness scaled with x/Ms for: (a) VRc = 0.3 and (b) VRc = 0.5

Grahic Jump Location
Fig. 9

Contours of uncorrected η at VR = 1.11 for VRc = 0.2, 0.4, and 0.6

Grahic Jump Location
Fig. 10

Jet characteristic parameters for DR = 1.2, VR = 1.11, (a) ηCL, (b) (z/d)CL, (c) W/d, and (d) S

Grahic Jump Location
Fig. 11

Jet parameters averaged over x/d = 5–20, DR = 1.2, VR = 1.11, (a) ηCL, (b) (z/d)CL, (c) W/d, and (d) S

Grahic Jump Location
Fig. 12:

Jet parameters averaged over x/d = 5–20, DR = 1.2 and 1.8, VR = 1.11, (a) ηCL and (b) (z/d)CL

Grahic Jump Location
Fig. 13

Discharge coefficients for all VRc tested at DR = 1.2: (a) scaled with PR (b) scaled with Uj/Uc

Grahic Jump Location
Fig. 14

Comparison of predicted φp and measured η, spatially averaged from x/d = 5–20, DR = 1.2

Grahic Jump Location
Fig. 15

Ratio of spatially averaged (x/d = 5–20) predicted overall effectiveness to predicted overall effectiveness without film cooling

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In