0
Research Papers

Full-Coverage Film Cooling: Film Effectiveness and Heat Transfer Coefficients for Dense and Sparse Hole Arrays at Different Blowing Ratios

[+] Author and Article Information
Phil Ligrani1

Department of Engineering Science  University of Oxford, Oxford, OX1 3PJ UKpligrani@slu.edu

Matt Goodro

Department of Engineering Science  University of Oxford, Oxford, OX1 3PJ UK

Mike Fox, Hee-Koo Moon

 Solar Turbines, Inc., San Diego, 92101 CA

1

Present address: Oliver L. Parks Endowed Chair, Department of Aerospace and Mechanical Engineering, Parks College of Engineering, Aviation, and Technology, Saint Louis University, 3450 Lindell Boulevard, McDonnell Douglas Hall Room 1033A, St. Louis, Missouri, 63103.

J. Turbomach 134(6), 061039 (Sep 17, 2012) (13 pages) doi:10.1115/1.4006304 History: Received August 02, 2011; Revised August 08, 2011; Published September 17, 2012; Online September 17, 2012

Experimental results are presented for a full coverage film cooling arrangement which simulates a portion of a gas turbine engine, with appropriate streamwise static pressure gradient and varying blowing ratio along the length of the contraction passage which contains the cooling hole arrangement. Film cooling holes are sharp-edged, streamwise inclined at 20 deg with respect to the liner surface, and are arranged with a length to diameter ratio of 8.35. The film cooling holes in adjacent streamwise rows are staggered with respect to each other. Data are provided for turbulent film cooling, contraction ratios of 1 and 4, blowing ratios (at the test section entrance) of 2.0, 5.0, and 10.0, coolant Reynolds numbers Refc from 10,000 to 12,000 (for a blowing ratio of 5.0), freestream temperatures from 75 °C to 115 °C, a film hole diameter of 7 mm, and density ratios from 1.15 to 1.25. Changes to X/D and Y/D, nondimensional streamwise and spanwise film cooling hole spacings, with Y/D of 3, 5, and 7, and with X/D of 6 and 18, are considered. For all X/D=6 hole spacings, only a slight increase in effectiveness (local, line-averaged, and spatially-averaged) values are present as the blowing ratio increases from 2.0 to 5.0, with no significant differences when the blowing ratio increases from 5.0 to 10.0. This lack of dependence on blowing ratio indicates a condition where excess coolant is injected into the mainstream flow, a situation not evidenced by data obtained with the X/D=18 hole spacing arrangement. With this sparse array configuration, local and spatially-averaged effectiveness generally increase continually as the blowing ratio becomes larger. Line-averaged and spatially-averaged heat transfer coefficients are generally higher at each streamwise location, also with larger variations with streamwise development, with the X/D=6 hole array, compared to the X/D=18 array.

Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Film cooling wind tunnel test facility

Grahic Jump Location
Figure 2

Film cooling test section

Grahic Jump Location
Figure 3

Film cooling test plate for X/D = 6, Y/D = 5 and hole angle 20 deg. (a) Test section dimensions and layout, where all dimensions are given in millimetres. (b) Test section coordinate system.

Grahic Jump Location
Figure 4

(a) Example of variation of local surface heat flux with surface temperature for one test surface location during a typical transient test. (b) Blowing ratio variation with x/D for different contraction ratios, calculated on the basis of static pressure ratios.

Grahic Jump Location
Figure 5

Spatially-resolved, local adiabatic effectiveness at different blowing ratios for hole spacings X/D=6, Y/D=3, and contraction ratio Cr=4, for (a) constant x/D=24 and (b) constant y/D=0

Grahic Jump Location
Figure 6

Spatially-resolved, local adiabatic effectiveness at different blowing ratios for hole spacings X/D=6, Y/D=5, and contraction ratio Cr=4, for (a) constant x/D=24 and (b) constant y/D=0

Grahic Jump Location
Figure 7

Spatially-resolved, local adiabatic effectiveness at different blowing ratios for hole spacings X/D=6, Y/D=7, and contraction ratio Cr=4, for (a) constant x/D=24 and (b) constant y/D=0

Grahic Jump Location
Figure 8

Line-averaged adiabatic film effectiveness at different blowing ratios for hole spacings X/D=6, Y/D=5, and contraction ratio Cr=4, with line-averaging over y/D

Grahic Jump Location
Figure 9

Variations of spatially-averaged adiabatic film effectiveness at different Y/D hole spacings for BR = 2.0, for streamwise hole spacing X/D of 6, and contraction ratio Cr of 4

Grahic Jump Location
Figure 10

Variations of spatially-averaged adiabatic film effectiveness at different Y/D hole spacings for BR = 5.0, for streamwise hole spacing X/D of 6, and contraction ratio Cr of 4

Grahic Jump Location
Figure 11

Variations of spatially-averaged adiabatic film effectiveness at different Y/D hole spacings for BR = 10.0, for streamwise hole spacing X/D of 6, and contraction ratio Cr of 4

Grahic Jump Location
Figure 12

Comparison of spatially-averaged adiabatic film effectiveness at different blowing ratios BR for streamwise hole spacing X/D of 6, spanwise hole spacing Y/D of 3, and contraction ratio Cr of 4

Grahic Jump Location
Figure 13

Comparison of spatially-averaged adiabatic film effectiveness at different blowing ratios BR for streamwise hole spacing X/D of 6, spanwise hole spacing Y/D of 5, and contraction ratio Cr of 4

Grahic Jump Location
Figure 14

Comparison of spatially-averaged adiabatic film effectiveness at different blowing ratios BR for streamwise hole spacing X/D of 6, spanwise hole spacing Y/D of 7, and contraction ratio Cr of 4

Grahic Jump Location
Figure 15

Spatially-resolved, local adiabatic effectiveness at different blowing ratios for hole spacings X/D=18, Y/D=5, and contraction ratio Cr=4, for (a) constant x/D=72 and (b) constant y/D=0

Grahic Jump Location
Figure 16

Comparison of spatially-averaged adiabatic film effectiveness at different blowing ratios BR for streamwise hole spacing X/D of 18, spanwise hole spacing Y/D of 5, and contraction ratio Cr of 4

Grahic Jump Location
Figure 17

Spatially-resolved local adiabatic film effectiveness at streamwise hole spacings, X/D=6 and X/D=18, for BR=5, Y/D=5, Cr=4, and (a) constant x/D=72 (X/D=18) and constant x/D=24 (X/D=6), and (b) constant y/D=0

Grahic Jump Location
Figure 18

Line-averaged adiabatic film effectiveness for X/D=6 and X/D=18, with Y/D = 5, a blowing ratio BR of 5.0, a contraction ratio Cr of 4, and line-averaging over y/D

Grahic Jump Location
Figure 19

Spatially-averaged adiabatic film effectiveness at streamwise hole spacings, X/D=6 and X/D=18, for Y/D = 5, Cr = 4, and different BR of 2.0, 5.0, and 10.0

Grahic Jump Location
Figure 20

Line-averaged heat transfer coefficients for X/D=6 and X/D=18, with Y/D = 5, a blowing ratio BR of 5.0, a contraction ratio Cr of 4, and line-averaging over y/D

Grahic Jump Location
Figure 21

Spatially-averaged heat transfer coefficients at streamwise hole spacings, X/D=6 and X/D=18, for Y/D = 5, a contraction ratio Cr of 4, and a blowing ratio BR of 5.0

Grahic Jump Location
Figure 22

Line-averaged net heat flux reduction (NHFR) values for X/D=6 and X/D=18, with Y/D = 5, a blowing ratio BR of 5.0, a contraction ratio Cr of 4, and line-averaging over y/D

Grahic Jump Location
Figure 23

Variation of acceleration parameter through the test section for contraction ratios Cr of 1 and 4

Grahic Jump Location
Figure 24

Variation of ratio of coolant mass flow rate to mainstream mass flow rate for X/D=6, with Y/D = 5, a blowing ratio BR of 5.0 for contraction ratios Cr of 1 and 4

Grahic Jump Location
Figure 25

Line-averaged adiabatic film effectiveness, with Y/D = 5, a blowing ratio BR of 5.0, contraction ratios Cr of 1 and 4, line-averaging over y/D., and for (a) X/D=6 and (b) X/D=18

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