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Research Papers

Film-Cooling Performance of a Turbine Vane Suction Side: The Showerhead Effect on Film-Cooling Hole Placement for Cylindrical and Fan-Shaped Holes

[+] Author and Article Information
Hossein Nadali Najafabadi

Department of Management and Engineering,
Linköping University,
Linköping 581 83, Sweden
e-mail: hossein.nadali.najafabadi@liu.se

Matts Karlsson

Department of Management and Engineering,
Linköping University,
Linköping 581 83, Sweden

Mats Kinell, Esa Utriainen

Siemens Industrial Turbomachinery AB,
Finspång 612 83, Sweden

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received September 1, 2014; final manuscript received March 3, 2015; published online March 17, 2015. Assoc. Editor: Kenichiro Takeishi.

J. Turbomach 137(9), 091005 (Sep 01, 2015) (11 pages) Paper No: TURBO-14-1224; doi: 10.1115/1.4029966 History: Received September 01, 2014; Revised March 03, 2015; Online March 17, 2015

In this paper, the transient IR-thermography method is used to investigate the effect of showerhead cooling on the film-cooling performance of the suction side of a turbine guide vane working under engine-representative conditions. The resulting adiabatic film effectiveness, heat transfer coefficient (HTC) augmentation, and net heat flux reduction (NHFR) due to insertion of rows of cooling holes at two different locations in the presence and absence of the showerhead cooling are presented. One row of cooling holes is located in the relatively high convex surface curvature region, while the other is situated closer to the maximum throat velocity. In the latter case, a double staggered row of fan-shaped cooling holes has been considered for cross-comparison with the single row at the same position. Both cylindrical and fan-shaped holes have been examined, where the characteristics of fan-shaped holes are based on design constraints for medium size gas turbines. The blowing rates tested are 0.6, 0.9, and 1.2 for single and double cooling rows, whereas the showerhead blowing is maintained at constant nominal blowing rate. The adiabatic film effectiveness results indicate that most noticable effects from the showerhead can be seen for the cooling row located on the higher convex surface curvature. This observation holds for both cylindrical and fan-shaped holes. These findings suggest that while the showerhead blowing does not have much impact on this cooling row from HTC enhancement perspective, it is influential in determination of the HTC augmentation for the cooling row close to the maximum throat velocity. The double-row fan-shaped cooling seems to be less affected by an upstream showerhead blowing when considering HTC enhancement, but it makes a major contribution in defining adiabatic film effectiveness. The NHFR results highlight the fact that cylindrical holes are not significantly affected by the showerhead cooling regardless of their position, but showerhead blowing can play an important role in determining the overall film-cooling performance of fan-shaped holes (for both the cooling row located on the higher convex surface curvature and the cooling row close to the maximum throat velocity), for both the single and the double row cases.

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References

Goldstein, R. J., Eckert, E. R. G., and Ramsey, J. W., 1968, “Film Cooling With Injection Through Holes: Adiabatic Wall Temperature Downstream of a Circular Hole,” ASME J. Eng. Power, 90(4), pp. 384–395. [CrossRef]
Jabbari, M. Y., and Goldstein, R. J., 1978, “Adiabatic Wall Temperature and Heat Transfer Downstream of Injection Through Two Rows of Holes,” ASME J. Eng. Power, 100(2), pp. 303–307. [CrossRef]
Lee, H. W., Park, J. J., and Lee, J. S., 2002, “Flow Visualization and Film Cooling Effectiveness Measurements Around Shaped Holes With Compound Angle Orientation,” Int. J. Heat Mass Transfer, 45(1), pp. 145–156. [CrossRef]
Yuen, C. H., and Martinez-Botas, R. F., 2005, “Film Cooling Characteristics of Rows of Round Holes at Various Streamwise Angles in a Crossflow: Part I. Film Effectiveness,” Int. J. Heat Mass Transfer, 48(23–24), pp. 4995–5016. [CrossRef]
Polanka, M., Witteveld, V., and Bogard, D. G., 1999, “Film Cooling Effectiveness in the Showerhead Region of a Gas Turbine Vane: Part I—Stagnation Region and Near-Pressure Side,” ASME Paper No. 99-GT-048. [CrossRef]
Nasir, S., Bolchoz, T., Zhang, L. J., Anthony, R. J., Moon, H. K., and Ng, W.-F., 2012, “Showerhead Film Cooling Performance of a Turbine Vane at High Freestream Turbulence in a Transonic Cascade,” ASME J. Turbomach., 134(5), p. 051021. [CrossRef]
Sargison, J., Guo, S., Lock, G., Rawlinson, A., and Oldfield, M., 2002, “A Converging Slot-Hole Film-Cooling Geometry—Part 2: Transonic Nozzle Guide Vane Heat Transfer and Loss,” ASME J. Turbomach., 124(3), pp. 461–471. [CrossRef]
Guo, S., Lai, C., Jones, T., Oldfield, M., Lock, G., and Rawlinson, A., 1998, “The Application of Thin-Film Technology to Measure Turbine-Vane Heat Transfer and Effectiveness in a Film-Cooled, Engine-Simulated Environment,” Int. J. Heat Fluid Flow, 19(6), pp. 594–600. [CrossRef]
Colban, W., Haendler, M., Gratton, A., and Thole, K., 2006, “Heat Transfer and Film-Cooling Measurements on a Stator Vane With Fan-Shaped Cooling Holes,” ASME J. Turbomach., 128(1), pp. 53–61. [CrossRef]
Zhang, L., Baltz, M., Pudupatty, R., and Fox, M., 1999, “Turbine Nozzle Film-Cooling Study Using the Pressure Sensitive Paint (PSP) Technique,” ASME Paper No. 99-GT-196. [CrossRef]
Zhang, L., and Pudupatty, R., 2000, “The Effects of Injection Angle and Hole Exit Shape on Turbine Nozzle Pressure Side Film-Cooling,” ASME Paper No. 2000-GT-0247. [CrossRef]
Nathan, M. L., Dyson, T. E., Bogard, D. G., and Bradshaw, S. D., 2014, “Adiabatic and Overall Effectiveness for the Showerhead Film Cooling of a Turbine Vane,” ASME J. Turbomach., 136(3), p. 031005 [CrossRef].
Kinell, M., Utriainen, E., Najafabadi, H. N., Karlsson, M., and Barabas, B., 2012, “Comparison of Gas Turbine Vane Pressure Side and Suction Side Film Cooling Performance and the Applicability of Superposition,” ASME Paper No. GT2012-68994. [CrossRef]
Schneider, M., Parneix, S., and von Wolfersdorf, J., 2003, “Effect of Showerhead Injection on Superposition of Multi-Row Pressure Side Film Cooling With Fan Shaped Holes,” ASME Paper No. GT2003-38693. [CrossRef]
Polanka, M., Ethridge, M., Cutbirth, J., and Bogard, D., 2000, “Effects of Showerhead Injection on Film Cooling Effectiveness for a Downstream Row of Holes,” ASME Paper No. 2000-GT-0240. [CrossRef]
Kinell, M., Utriainen, E., Hylén, J., Gustavsson, J., Bradley, A., Karlsson, M., and Wren, J., 2010, “Fan Shaped and Cylindrical Holes Studied in Vane Film Cooling Test Rig,” ASME Paper No. GT2010-23308. [CrossRef]
Reiss, H., Drost, U., and Bölcs, A., 1998, “The Transient Liquid Crystal Technique Employed for Sub- and Transonic Heat Transfer and Film Cooling Measurements in a Linear Cascade,” 14th Bi-Annual Symposium on Measuring Techniques in Transonic and Supersonic Flow in Cascades and Turbomachines, Limerick, Ireland, Sept. 3–5, Paper No. LTT-CONF-1998-007.
Schlichting, H., 1968, Boundary Layer Theory, 6th ed., McGraw-Hill, New York, p. 295.
Moffat, R. J., 1985, “Using Uncertainty Analysis in the Planning of an Experiment,” ASME J. Fluids Eng.107(2), pp. 173–178. [CrossRef]
Gustavsson, J., Hylen, J., Kinell, M., and Utriainen, E., 2010, “Window Temperature Impact on IR Thermography for Heat Transfer Measurement,” AIAA Paper No. 2010-0670. [CrossRef]
Baldauf, S., Scheurlen, M., Schulz, A., and Wittig, S., 2002, “Heat Flux Reduction From Film Cooling and Correlation of Heat Transfer Coefficients From Thermographic Measurements at Engine Like Conditions,” ASME Paper No. GT2002-30181. [CrossRef]
Sellers, J. P., 1963, “Gaseous Film Cooling With Multiple Injection Stations,” AIAA J., 1(9), pp. 2154–2156. [CrossRef]
Nadali, H. N., Karlsson, M., Kinell, M., and Utriainen, E., 2012, “CFD Based Sensitivity Analysis of Influencing Flow Parameters for Cylindrical and Shaped Holes in a Gas Turbine Vane,” ASME Paper No. GT2012-69023. [CrossRef]
Bunker, R. S., 2005, “A Review of Shaped Hole Turbine Film-Cooling Technology,” ASME J. Heat Transfer, 127(4), pp. 441–453. [CrossRef]
Gritsch, M., Schulz, A., and Wittig, S., 1998, “Heat Transfer Coefficient Measurements of Film-Cooling Holes With Expanded Exits,” ASME Paper No. 98-GT-028. [CrossRef]
Mehendale, A. B., and Je-Chin, H., 1993, “Reynolds Number Effect on Leading Edge Film Effectiveness and Heat Transfer Coefficient,” Int. J. Heat Mass Transfer, 36(15), pp. 3723–3730. [CrossRef]
Lu, Y., Bunker, R. S., Dhungel, A., and Ekkad, S. V., 2009, “Effect of Trench Width and Depth on Film Cooling From Cylindrical Holes Embedded in Trenches,” ASME J. Turbomach., 131(1), p. 011003. [CrossRef]
Drost, U., and Bolcs, A., 1999, “Investigation of Detailed Film Cooling Effectiveness and Heat Transfer Distributions on a Gas Turbine Airfoil,” ASME J. Turbomach., 121(2), pp. 233–242. [CrossRef]

Figures

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Fig. 1

Experimental setup indicating the bypass valve denoted as P, pneumatic actuator, and test section with corresponding dimensions

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Fig. 2

The prototype vane with showerhead cooling, positions, and numbering of the film-cooling rows. The cavities supplying cooled air are marked C1–C3. The surface length S is defined such that S = 0 indicates the position of stagnation point. Accordingly, S  >  0 and S  <  0 denote the suction and pressure sides, respectively.

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Fig. 3

Fan-shaped cooling hole detailed geometry, to the left, cylindrical hole parameters and radial angle for showerhead cooling holes, to the right

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Fig. 4

Nondimensional pressure distribution Cp

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Fig. 5

Nondimensional freestream and surface temperature as function of Fourier number (nondimensional time). The freestream temperature represents the step change in the main-flow temperature after the bypassed time (indicated by dashed line) in which the valve is opened and the heated air is entered into the test section.

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Fig. 6

Comparison of raw data and smoothed data for cooling row #1, fan-shaped without showerhead cooling: (a) laterally averaged film-cooling effectiveness (η) and (b) laterally averaged Nusselt number (Nu)

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Fig. 7

Comparison of laterally averaged adiabatic film effectiveness for cooling row #1 with and without showerhead cooling: (a) cylindrical hole and (b) fan-shaped hole

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Fig. 8

Comparison of laterally averaged adiabatic film effectiveness for cooling row #3 with and without showerhead cooling: (a) cylindrical hole and (b) fan-shaped hole. For legend, see Fig. 7.

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Fig. 9

The superposition effect for laterally averaged adiabatic film effectiveness for M = 0.6 (a) cooling row #1 and (b) cooling row #3

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Fig. 10

Comparison of laterally averaged adiabatic film effectiveness for double staggered row cooling (rows #2 and #3) with and without showerhead cooling for fan-shaped holes. Note, S/D = 0 indicates the cooling hole center of row #3. For legend, see Fig. 7.

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Fig. 11

Laterally averaged Nu of uncooled (smooth) vane and showerhead cooling on the suction side. Position of the showerhead cooling as well as cooling rows #1 and #3 is denoted by vertical dashed lines.

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Fig. 12

Comparison of laterally averaged HTC augmentation for cooling row #1 with and without showerhead cooling: (a) cylindrical hole and (b) fan-shaped hole. For legend, see Fig. 7.

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Fig. 13

Comparison of laterally averaged HTC augmentation for cooling row #3 with and without showerhead cooling: (a) cylindrical hole and (b) fan-shaped hole. For legend, see Fig. 7.

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Fig. 14

Comparison of laterally averaged HTC augmentation for double-row cooling (rows #2 and #3) with and without showerhead cooling for fan-shaped holes: (a) cylindrical hole and (b) fan-shaped hole. Note, S/D = 0 indicates the cooling hole center of row #3. For legend, see Fig. 7.

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Fig. 15

Comparison of laterally averaged NHFR for cooling row #1 with and without showerhead cooling: (a) cylindrical hole and (b) fan-shaped hole. For legend, see Fig. 7.

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Fig. 16

Comparison of laterally averaged NHFR for cooling row #3 with and without showerhead cooling: (a) cylindrical hole and (b) fan-shaped hole. For legend, see Fig. 7.

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Fig. 17

Comparison of laterally averaged NHFR for double-row cooling (rows #2 and #3) with and without showerhead cooling for fan-shaped hole. Note, S/D = 0 indicates the cooling hole center of row #3. For legend, see Fig. 7.

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