Research Papers

Heat Transfer Measurements in a Leading Edge Geometry With Racetrack Holes and Film Cooling Extraction

[+] Author and Article Information
Francesco Maiuolo

e-mail: francesco.maiuolo@htc.de.unifi.it

Lorenzo Tarchi

“S. Stecco” Energy Engineering Department,
University of Florence,
Via S. Marta, 3, 50139 Florence, Italy

Stefano Zecchi

Engineering, Research & Development,
AVIO S.p.A., Via Primo Maggio 56,
Rivalta di Torino,
Turin 10040, Italy
e-mail: stefano.zecchi@aviogroup.com

1Corresponding author.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the Journal of Turbomachinery. Manuscript received June 29, 2012; final manuscript received August 6, 2012; published online March 25, 2013. Editor: David Wisler.

J. Turbomach 135(3), 031020 (Mar 25, 2013) (9 pages) Paper No: TURBO-12-1097; doi: 10.1115/1.4007527 History: Received June 29, 2012; Revised August 06, 2012

An experimental survey on a state of the art leading edge cooling scheme was performed to evaluate heat transfer coefficients (HTC) on a large scale test facility simulating a high pressure turbine airfoil leading edge cavity. The test section includes a trapezoidal supply channel with three large racetrack impingement holes. On the internal surface of the leading edge, four big fins are placed in order to confine impingement jets. The coolant flow impacts the leading edge internal surface, and it is extracted from the leading edge cavity through 24 showerhead holes and 24 film cooling holes. The aim of the present study is to investigate the combined effects of jet impingement and mass flow extraction on the internal heat transfer of the leading edge. A nonuniform mass flow extraction was also imposed to reproduce the effects of the pressure side and suction side external pressure. Measurements were performed by means of a transient technique using narrow band thermochromic liquid crystals (TLCs). Jet Reynolds number and crossflow conditions into the supply channel were varied in order to cover the typical engine conditions of these cooling systems (Rej=10,000-40,000). Experiments were compared with a numerical analysis on the same test case in order to better understand flow interaction inside the cavity. Results are reported in terms of detailed 2D maps, radial-wise, and span-wise averaged values of Nusselt number.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Fig. 2

SH and FC mass flow extraction

Grahic Jump Location
Fig. 3

Crossflow conditions scheme

Grahic Jump Location
Fig. 4

CFD setup: (up) numerical domain; (down) numerical grid

Grahic Jump Location
Fig. 5

Nu/Nuavg maps at Rej = 10,000 – 20,000 – 30,000

Grahic Jump Location
Fig. 6

Nusselt number averaged values

Grahic Jump Location
Fig. 7

Comparison with published data

Grahic Jump Location
Fig. 8

Central module, %Cr=40: velocity streamlines

Grahic Jump Location
Fig. 9

Central module, %Cr=40: coolant jet impinging zones




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