0
Research Papers

Adiabatic Film Cooling Effectiveness Measurements Throughout Multirow Film Cooling Arrays

[+] Author and Article Information
Greg Natsui

Center for Advanced Turbomachinery
and Energy Research,
Laboratory for Turbine Aerodynamics,
Heat Transfer and Durability,
University of Central Florida,
Orlando, FL 32816
e-mail: gnatsui@knights.ucf.edu

Zachary Little

Center for Advanced Turbomachinery
and Energy Research,
Laboratory for Turbine Aerodynamics,
Heat Transfer and Durability,
University of Central Florida,
Orlando, FL 32816
e-mail: Zachary.Little@ucf.edu

Jayanta S. Kapat

Center for Advanced Turbomachinery
and Energy Research,
Laboratory for Turbine Aerodynamics,
Heat Transfer and Durability,
University of Central Florida,
Orlando, FL 32816
e-mail: Jayanta.Kapat@ucf.edu

Jason E. Dees

GE Global Research,
Niskayuna, NY 12309
e-mail: DeesJ@ge.com

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received September 20, 2016; final manuscript received November 7, 2016; published online May 16, 2017. Editor: Kenneth Hall.

J. Turbomach 139(10), 101008 (May 16, 2017) (12 pages) Paper No: TURBO-16-1247; doi: 10.1115/1.4035520 History: Received September 20, 2016; Revised November 07, 2016

Adiabatic film cooling effectiveness measurements are obtained using pressure-sensitive paint (PSP) on a flat film cooled surface. The effects of blowing ratio and hole spacing are investigated for four multirow arrays comprised of eight rows containing 52 holes of 3.8 mm diameter with 20 deg inclination angles and hole length-to-diameter ratio of 11.2. The four arrays investigated have two different hole-to-hole spacings composed of cylindrical and diffuser holes. For the first case, lateral and streamwise pitches are 7.5 times the diameter. For the second case, pitch-to-diameter ratio is 14 in lateral direction and 10 in the streamwise direction. The holes are in a staggered arrangement. Adiabatic effectiveness measurements are taken for a blowing ratio range of 0.3–1.2 and a density ratio of 1.5, with CO2 injected as the coolant. A thorough boundary layer analysis is presented, and data were taken using hotwire anemometry with air injection, with boundary layer, and turbulence measurements taken at multiple locations in order to characterize the boundary layer. Local effectiveness, laterally averaged effectiveness, boundary layer thickness, momentum thickness, turbulence intensity, and turbulence length scale are presented. For the cylindrical holes, at the first row of injection, the film jets are still attached at a blowing ratio of 0.3. By a blowing ratio of 0.5, the jet is observed to lift off, and then impinge back onto the test surface. At a blowing ratio of 1.2, the jets lift off, but reattach much further downstream, spreading the coolant further along the test surface. A thorough uncertainty analysis has been conducted in order to fully understand the presented measurements and any shortcomings of the measurement technique. The maximum uncertainty of effectiveness and blowing ratio is 0.02 counts of effectiveness and 3%, respectively.

Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Parametric space for multirow film; literature and present study

Grahic Jump Location
Fig. 2

Isometric view of wind tunnel showing main components

Grahic Jump Location
Fig. 3

Cross-sectional view of wind tunnel showing coolant flow conditioning and measurement locations for pressure and temperature

Grahic Jump Location
Fig. 4

Streamwise pressure gradient in wind tunnel primary flow

Grahic Jump Location
Fig. 5

K(x), acceleration parameter throughout the test section

Grahic Jump Location
Fig. 6

Diffuser-shaped hole studied by Gritsch et al. [16]

Grahic Jump Location
Fig. 7

New diffuser modeled after the fan-shaped hole studied by Gritsch et al.

Grahic Jump Location
Fig. 8

Inner scaled boundary layer upstream of film cooling array

Grahic Jump Location
Fig. 10

Gas sampling tap locations, shown on geometry 5

Grahic Jump Location
Fig. 11

Geometry 1, M = 0.30; spatially resolved η

Grahic Jump Location
Fig. 12

Geometry 1, M = 0.79; spatially resolved η

Grahic Jump Location
Fig. 13

Geometry 1, M = 1.23; spatially resolved η

Grahic Jump Location
Fig. 14

Geometry 1b, M = 0.30; spatially resolved η

Grahic Jump Location
Fig. 15

Geometry 1b, M = 0.81; spatially resolved η

Grahic Jump Location
Fig. 16

Geometry 1b, M = 1.34; spatially resolved η

Grahic Jump Location
Fig. 17

Geometry 2, M = 0.30; spatially resolved η

Grahic Jump Location
Fig. 18

Geometry 2, M = 0.75; spatially resolved η

Grahic Jump Location
Fig. 19

Geometry 2, M = 1.20; spatially resolved η

Grahic Jump Location
Fig. 20

Geometry 5, M = 0.55; spatially resolved η

Grahic Jump Location
Fig. 21

Geometry 5, M = 1.05; spatially resolved η

Grahic Jump Location
Fig. 22

Geometry 5, M = 2.20; spatially resolved η

Grahic Jump Location
Fig. 23

Geometry 6, M = 0.53; spatially resolved η

Grahic Jump Location
Fig. 24

Geometry 6, M = 1.59; spatially resolved η

Grahic Jump Location
Fig. 25

Geometry 6, M = 2.20; spatially resolved η

Grahic Jump Location
Fig. 26

Geometry 1: uη(xi/d,zi/d;M=0.30) spatially resolved uncertainty estimate

Grahic Jump Location
Fig. 27

Geometry 1: uη(xi/d,zi/d;M=0.79) spatially resolved uncertainty estimate

Grahic Jump Location
Fig. 28

Geometry 1: uη(xi/d,zi/d;M=1.20) spatially resolved uncertainty estimate

Grahic Jump Location
Fig. 29

Geometry 1: uη(η;M=0.30), relation between uncertainty in effectiveness with effectiveness, incorporating all random error sources beginning with intensities

Grahic Jump Location
Fig. 30

η¯(xi/d;M) for geometry 1

Grahic Jump Location
Fig. 31

η¯(xi/d;M) for geometry 1 b

Grahic Jump Location
Fig. 32

η¯(xi/d;M) for geometry 2

Grahic Jump Location
Fig. 33

η¯(xi/d;M) for geometry 5

Grahic Jump Location
Fig. 34

η¯(xi/d;M) for geometry 6

Grahic Jump Location
Fig. 35

η(x/d,Pz/4;M=0.6) comparison to gas sampling results

Grahic Jump Location
Fig. 36

η(x/d,Pz/4;M=0.75) comparison to gas sampling results

Grahic Jump Location
Fig. 37

η(x/d,Pz/4;M=0.9) comparison to gas sampling results

Grahic Jump Location
Fig. 38

Repeatability of gas sampling results

Grahic Jump Location
Fig. 39

Superposition prediction of multirow cooling based on single-row results for M = 0.3, 0.5, and 0.9

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