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.

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Metzger, D., and Bunker, R., 1990, “Local Heat Transfer in Internally Cooled Turbine Airfoil Leading Edge Regions: Part II—Impingement Cooling With Film Coolant Extraction,” ASME J. Turbomach., 112, pp. 459–466. [CrossRef]
Metzger, D., Yamashita, T., and Jenkins, C., 1969, “Impingement Cooling of Concave Surfaces With Lines of Circular Air Jets,” ASME J. Eng. Power, 91(3), pp. 149–155. [CrossRef]
Metzger, D., Takeuchi, D., and Kuenstler, P., 1973, “Effectiveness and Heat Transfer With Full-Coverage Film Cooling,” ASME J. Eng. Power, 95, pp. 180–184. [CrossRef]
Kercher, D., and Tabakoff, W., 1970, “Heat Transfer by a Square Array of Round Air Jets Impinging Perpendicular to Flat Surface Including the Effect of Spent Air,” ASME J. Eng. Power, 92, pp. 73–82. [CrossRef]
Martin, H., 1977, “Heat and Mass Transfer Between Impinging Gas Jets and Solid Surfaces,” Adv. Heat Transfer, 13, pp. 1–60. [CrossRef]
Florschuetz, L., Truman, C., and Metzger, D., 1981, “Streamwise Flow and Heat Transfer Distributions for Jet Array Impingement With Crossflow,” ASME J. Heat Transfer, 103, pp. 337–342. [CrossRef]
Florschuetz, L., Metzger, D., Su, C., Isoda, Y., and Tseng, H., 1984, “Heat Transfer Characteristics for Jet Arrays Impingement With Initial Crossflow,” ASME J. Heat Transfer, 106, pp. 34–41. [CrossRef]
Behbahani, A., and Goldstein, R., 1983, “Local Heat Transfer to Staggered Arrays of Impinging Circular Air Jets,” ASME J. Eng. Power, 105, pp. 354–360. [CrossRef]
Chupp, R., Helms, H., McFadden, P., and Brown, T., 1969, “Evaluation of Internal Heat Transfer Coefficients for Impingement Cooled Turbine Blades,” J. Aircr., 6, pp. 203–208. [CrossRef]
Metzger, D., Baltzer, R., and Jenkins, C., 1972, “Impingement Cooling Performance in Gas Turbine Airfoils Including Effects of Leading Edge Sharpness,” ASME J. Eng. Power, 94, pp. 219–225. [CrossRef]
Hrycak, P., 1981, “Heat Transfer From a Row of Impinging Jets to Concave Cylindrical Surfaces,” Int. J. Heat Mass Transfer, 24, pp. 407–419. [CrossRef]
Metzger, D., and Bunker, R., 1990, “Local Heat Transfer in Internally Cooled Turbine Airfoil Leading Edge Regions: Part I—Impingement Cooling Without Film Coolant Extraction,” ASME J. Turbomach., 112, pp. 451–458. [CrossRef]
Taslim, M. E., Pan, Y., and Spring, S. D., 2001, “An Experimental Study of Impingement on Roughened Airfoil Leading-Edge Walls With Film Holes,” ASME J. Turbomach., 123, pp. 766–773. [CrossRef]
Taslim, M., Bakhtari, K., and Liu, H., 2003, “Experimental and Numerical Investigation of Impingement on a Rib-Roughened Leading-Edge Wall,” ASME Paper No. GT2003-38118. [CrossRef]
Taslim, M., and Bethka, D., 2007, “Experimental and Numerical Impingement Heat Transfer in an Airfoil Leading-Edge Cooling Channel With Crossflow,” ASME Paper No. GT2007-28212. [CrossRef]
Elebiary, K., and Taslim, M., 2011, “Experimental/Numerical Crossover Jet Impingement in an Airfoil Leading-Edge Cooling Channel,” ASME Paper No. GT2011-46004. [CrossRef]
Chan, T. L., Ashforth-Frost, S., and Jambunathan, K., 2001, “Calibrating for Viewing Angle Effect During Heat Transfer Measurements on a Curved Surface,” Int. J. Heat Mass Transfer, 44, pp. 2209–2223. [CrossRef]
Ireland, P. T., Wang, Z., and Jones, T. V., 1993, “Liquid Crystal Heat Transfer Measurements,” Measurement Techniques (Lecture Series 1993-05), von Karman Institute for Fluid Dynamics, Rhode-Saint-Genèse, Belgium.
Camci, C., 1995, “Liquid Crystal Thermography,” Temperature Measurements (Lecture Series 1996-07), von Karman Institute for Fluid Dynamics, Rhode-Saint-Genèse, Belgium.
Graham, D., and Rhine, J., 2000, “The Design of Transient Wall Heating Experiments for the Determination of Convective Heat Transfer Using Liquid Crystal Thermography,” ASME Paper No. GT2000-0658.
ASME, 1985, “Measurement Uncertainty,” Instrument and Apparatus, ANSI/ASME PTC 19.1-1985, ASME, New York.
Kline, S. J., and McClintock, F. A., 1953, “Describing Uncertainties in Single Sample Experiments,” Mech. Eng., 75, pp. 3–8.


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Fig. 2

SH and FC mass flow extraction

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Fig. 3

Crossflow conditions scheme

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Fig. 4

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

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Fig. 5

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

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Fig. 6

Nusselt number averaged values

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Fig. 7

Comparison with published data

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Fig. 8

Central module, %Cr=40: velocity streamlines

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Fig. 9

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



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