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Research Papers

Experimental Simulation of Contaminant Deposition on a Film-Cooled Turbine Vane Pressure Side With a Trench

[+] Author and Article Information

Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712

1Present address: GE Energy, Greenville, SC.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the Journal of Turbomachinery. Manuscript received April 28, 2012; final manuscript received September 30, 2012; published online June 26, 2013. Editor: David Wisler.

J. Turbomach 135(5), 051008 (Jun 26, 2013) (11 pages) Paper No: TURBO-12-1036; doi: 10.1115/1.4007821 History: Received April 28, 2012; Revised September 30, 2012

An important issue in the use of coal- or biomass-derived synthetic gaseous (syngas) fuels is the deposition of contaminants on film-cooled turbine surfaces, which alter cooling and aerodynamic performance and increase material degradation. The current study applied a new experimental technique that simulated the key physical aspects of contaminant deposition on a film-cooled turbine vane. The depositing contaminants were modeled in a wind tunnel facility with a spray of molten wax droplets of a size range that matched the Stokes number of the contaminant particles in engine conditions. Most experiments were performed using a vane model with a thermal conductivity selected such that the model had the same Biot number of an actual engine airfoil, resulting in a cooler surface temperature. Some experiments were performed using an approximately adiabatic model for comparison. The film cooling design consisted of three rows of showerhead cooling at the leading edge and one row of body film cooling holes on the pressure side. Two designs of pressure side body film cooling holes were considered: a standard design of straight, cylindrical holes and an advanced design of “trenched” cooling holes in which the hole exits were situated in a recessed, transverse trench. The results showed thin deposits formed in the trench, with the thickest deposits on its downstream wall between coolant jets. Adiabatic film effectiveness levels were essentially unchanged by the presence of deposits for either film configuration. Deposit formation was strongly influenced by the model surface temperature with cooler surfaces inhibiting deposition. There was evidence of a threshold surface temperature above which deposits became significantly thicker.

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References

Walsh, P. M., Sayre, A. N., Loehden, D. O., Monroe, L. S., Beér, J. M., and Sarofim, A. F., 1990, “Deposition of Bituminous Coal Ash on an Isolated Heat Exchanger Tube: Effects of Coal Properties on Deposit Growth,” Prog. Energ. Combust., 16, pp. 327–346. [CrossRef]
Rosner, D. E., and Nagarajan, R., 1987, “Toward a Mechanistic Theory of Net Deposit Growth From Ash-Laden Flowing Combustion Gases: Self-Regulated Sticking of Impacting Particles and Deposit Erosion in the Presence of Vapor Deposited—or Submicron Mist—‘Glue,’” AIChE Symposium Series, Heat Transfer, Pittsburgh, PA, August 9–12, 1987, pp. 289–296.
Wenglarz, R. A., and Fox, R. G., 1990, “Physical Aspects of Deposition From Coal-Water Fuels Under Gas Turbine Conditions,” ASME J. Eng. Gas Turb. Power, 112, pp. 9–14. [CrossRef]
Crosby, J. M., Lewis, S., Bons, J. P., Ai, W., and Fletcher, T. H., 2008, “Effects of Temperature and Particle Size on Deposition in Land Based Turbines,” ASME J. Eng. Gas Turb. Power, 130, p. 051503. [CrossRef]
Ai, W., Laylock, R. G., Rappleye, D. S., Fletcher, T. H., and Bons, J. P., 2009, “Effect of Particle Size and Trench Configuration on Deposition From Fine Coal Flyash Near Film Cooling Holes,” ASME Paper No. GT2009-59571. [CrossRef]
Lewis, S., Barker, B., Bons, J. P., Ai, W., and Fletcher, T. H., 2011, “Film Cooling Effectiveness and Heat Transfer Near Deposit-Laden Film Holes,” ASME J. Turbomach., 133, p. 031003. [CrossRef]
Albert, J. E., Keefe, K. J., and Bogard, D. G., 2009, “Experimental Simulation of Contaminant Deposition on a Film Cooled Turbine Airfoil Leading Edge,” ASME Paper No. IMECE2009-11582. [CrossRef]
Lawson, S. A., and Thole, K. A., 2010, “Simulations of Multi-Phase Particle Deposition on End Wall Film-Cooling,” ASME Paper No. GT2010-22376. [CrossRef]
Bunker, R. S., 2002, “Film Cooling Effectiveness Due to Discrete Holes Within a Transverse Surface Slot,” ASME Paper No. GT2002-30178. [CrossRef]
Waye, S. K., and Bogard, D. G., 2007, “High-Resolution Film Cooling Effectiveness Measurements of Axial Holes Embedded in a Transverse Trench With Various Trench Configurations,” ASME J. Turbomach., 129(2), pp. 294–302. [CrossRef]
Dorrington, J. R., Bogard, D. G., and Bunker, R. S., 2007, “Film Effectiveness Performance for Coolant Holes Embedded in Various Shallow Trench and Crater Depressions,” ASME Paper No. GT2007-27992. [CrossRef]
Albert, J. E., and Bogard, D. G., 2011, “Measurements of Adiabatic Film and Overall Cooling Effectiveness on a Turbine Vane Pressure Side With a Trench,” ASME Paper No. GT2011-46703. [CrossRef]
Hylton, L. D., Milhec, M. S., Turner, E. R., Nealy, D. A., and York, R. E., 1983, “Analytical and Experimental Evaluation of the Heat Transfer Distribution Over the Surface of Turbine Vanes,” NASA CR 168015.
Moffat, R. J., 1988, “Describing the Uncertainties in Experimental Results,” Exper. Therm., 1, pp. 3–17. [CrossRef]
Hinds, W. C., 1999, Aerosol Technology: Properties, Behavior, and Measurement of Airborne Particles, 2nd ed., Wiley-Interscience, New York.
Bons, J. P., Crosby, J., Wammack, J. E., Bentley, B. I., and Fletcher, T. H., 2007, “High Pressure Turbine Deposition in Land-Based Gas Turbines From Various Synfuels,” ASME J. Eng. Gas Turb. Power, 129, pp. 135–143. [CrossRef]

Figures

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Fig. 1

Wind tunnel test section schematic

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Fig. 2

Vane model cross section schematic with hatch locations shown

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Fig. 3

PS film row trenched cooling hole schematic

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Fig. 4

Wax spray device (a) schematic and (b) photo in situ

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Fig. 5

Scanning electron microscope image of wax spray sample

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Fig. 6

Photo of deposits: nonfilm-cooled, isothermal vane (T = Tc = 305 K) (maximum tdep = 3.1 mm at location marked by a circle)

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Fig. 7

Photo of deposits: nonfilm-cooled, internally cooled vane (T = 305 K, Tc = 220 K, DR = 1.4) (maximum tdep = 5.3 mm at location marked by a circle)

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Fig. 8

Photo of deposits: film-cooled, matched-Bi vane with standard PS holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4)

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Fig. 9

Photo of deposits: film-cooled, matched-Bi vane, with standard PS holes, lower blowing ratio (MPS = 1.0, M*Shd = 0.75, DR = 1.4)

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Fig. 10

Detailed photos of deposits at showerhead for different blowing ratios (DR = 1.4)

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Fig. 11

Photo of deposits: film-cooled, low-conductivity vane with standard PS holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4)

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Fig. 12

Detailed photos of deposits at standard PS film holes for different model conductivities (DR = 1.4)

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Fig. 13

Laterally averaged ϕ and η for the vane with showerhead + standard PS holes, prior to deposition (MPS = 2.0, M*Shd = 2.0, DR = 1.4) (these data correspond to the conditions used to simulate deposits shown in Figs. 8 and 11)

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Fig. 14

Laterally averaged deposit thickness for the vane models with showerhead + standard PS holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4) (these data correspond to the deposits shown in Figs. 8 and 11)

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Fig. 15

Photo of deposits: film-cooled, matched-Bi vane with trenched PS holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4)

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Fig. 16

Detailed photos of deposits at standard and trenched PS film holes (DR = 1.4)

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Fig. 17

Effect of deposits on laterally averaged η for standard and trenched PS film holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4)

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Fig. 18

Effect of deposits on η contours for standard and trenched PS film holes (MPS = 2.0, M*Shd = 2.0, DR = 1.4)

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