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Research Papers

Dynamics of Coherent Structures and Random Turbulence in Pressure Side Film Cooling on a First Stage Turbine Vane

[+] Author and Article Information
S. Ravelli

Department of Engineering and
Applied Sciences,
University of Bergamo,
Marconi Street 5,
Dalmine 24044 (BG), Italy
e-mail: silvia.ravelli@unibg.it

G. Barigozzi

Department of Engineering and
Applied Sciences,
University of Bergamo,
Marconi Street 5,
Dalmine 24044 (BG), Italy
e-mail: giovanna.barigozzi@unibg.it

1Corresponding author.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received July 26, 2018; final manuscript received September 26, 2018; published online October 17, 2018. Editor: Kenneth Hall.

J. Turbomach 141(1), 011003 (Oct 17, 2018) (11 pages) Paper No: TURBO-18-1172; doi: 10.1115/1.4041602 History: Received July 26, 2018; Revised September 26, 2018

This paper collects the final results of a combined experimental and numerical investigation on pressure side (PS) film cooling in a high-pressure turbine vane, including two staggered rows of cylindrical holes and a trailing edge cutback, fed by one plenum. Having learned that the scale resolving simulation technique is essential to get reasonable predictions of adiabatic film cooling effectiveness, the stress-blended eddy simulation (SBES) model has been selected as the best among the available hybrid RANS–LES options. Mainstream conditions were limited to low speed and low turbulence intensity due to the need of high temporal and spatial resolution. The choice of one only coolant-to-mainstream mass flow ratio equal to MFR = 1.5% was dictated by the hole discharge: on the one side, mainstream injection into the cooling holes and, on the other side, jet liftoff were avoided to get an effective thermal coverage downstream of the holes. SBES potential was evaluated on the basis of qualitative and quantitative characteristics of the flow along the interface between coolant and mainstream because of their ultimate effect on vane surface temperature. The focus was set on shape and dynamics of coherent structures: SBES provided evidence of shear layer Kelvin–Helmholtz instability and hairpin vortices, downstream of cooling holes, with a Strouhal number (St) of 1.3 and 0.3–0.4, respectively. Simulated vortex shedding in the cutback region was characterized by St of 0.32 to be compared against the measured St value of 0.40.

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References

Logan , E., Jr. , 2003, Handbook of Turbomachinery, CRC Press, Boca Raton, FL.
Dixon, S. L. , and Hall, C. , 2013, Fluid Mechanics and Thermodynamics of Turbomachinery, Butterworth-Heinemann, Oxford, UK.
Han, J. C. , Dutta, S. , and Ekkad, S. , 2012, Gas Turbine Heat Transfer and Cooling Technology, CRC Press, Boca Raton, FL.
Acharya, S. , 2015, “ The Physics of Film Cooling Flow and Heat Transfer,” CHT-15: 6th International Symposium on Advances in Computational Heat Transfer, Piscataway, NJ, May 25–29, pp. 1812–1815.
Fawcett, R. J. , Wheeler, A. P. , He, L. , and Taylor, R. , 2012, “ Experimental Investigation Into Unsteady Effects on Film Cooling,” ASME J. Turbomach., 134(2), p. 021015. [CrossRef]
Fawcett, R. J. , Wheeler, A. P. , He, L. , and Taylor, R. , 2013, “ Experimental Investigation Into the Impact of Crossflow on the Coherent Unsteadiness Within Film Cooling Flows,” Int. J. Heat Fluid Flow, 40, pp. 32–42. [CrossRef]
Kohli, A. , and Bogard, D. G. , 1998, “ Effects of Very High Free-Stream Turbulence on the Jet-Mainstream Interaction in a Film Cooling Flow,” ASME J. Turbomach., 120(4), pp. 785–790. [CrossRef]
Rouina, S. , Miranda, M. , and Barigozzi, G. , 2016, “ Experimental Investigation of the Unsteady Flow Behavior on a Film Cooling Flat Plate,” Energy Procedia, 101, pp. 726–733. [CrossRef]
Eberly, M. K. , and Thole, K. A. , 2014, “ Time-Resolved Film-Cooling Flows at High and Low Density Ratios,” ASME J. Turbomach., 136(6), p. 061003. [CrossRef]
Ziefle, J. , and Kleiser, L. , 2013, “ Numerical Investigation of a Film-Cooling Flow Structure: Effect of Crossflow Turbulence,” ASME J. Turbomach., 135(4), p. 041001. [CrossRef]
Kalghatgi, P. , and Acharya, S. , 2014, “ Modal Analysis of Inclined Film Cooling Jet Flow,” ASME J. Turbomach., 136(8), p. 081007. [CrossRef]
Straußwald, M. , Schmid, K. , Müller, H. , and Pfitzner, M. , 2017, “ Experimental and Numerical Investigation of Turbulent Mixing in Film Cooling Applications,” ASME Paper No. GT2017-64650.
Benson, M. J. , Elkins, C. J. , and Eaton, J. K. , 2011, “ Measurements of 3D Velocity and Scalar Field for a Film-Cooled Airfoil Trailing Edge,” Exp. Fluids, 51(2), pp. 443–455. [CrossRef]
Ling, J. , Yapa, S. D. , Benson, M. J. , Elkins, C. J. , and Eaton, J. K. , 2013, “ Three-Dimensional Velocity and Scalar Field Measurements of an Airfoil Trailing Edge With Slot Film Cooling: The Effect of an Internal Structure in the Slot,” ASME J. Turbomach., 135(3), p. 031018. [CrossRef]
Yang, Z. , and Hu, H. , 2012, “ An Experimental Investigation on the Trailing Edge Cooling of Turbine Blades,” Propul. Power Res., 1(1), pp. 36–47. [CrossRef]
Holloway, D. S. , Leylek, J. H. , and Buck, F. A. , 2002, “ Pressure-Side Bleed Film Cooling—Part II: Unsteady Framework for Experimental and Computational Results,” ASME Paper No. GT-2002-30472.
Martini, P. , Schulz, A. , Bauer, H. J. , and Whitney, C. F. , 2006, “ Detached Eddy Simulation of Film Cooling Performance on the Trailing Edge Cutback of Gas Turbine Airfoils,” ASME J. Turbomach., 128(2), pp. 292–299. [CrossRef]
Joo, J. , and Durbin, P. , 2009, “ Simulation of Turbine Blade Trailing Edge Cooling,” ASME J. Fluids Eng., 131(2), p. 021102. [CrossRef]
Effendy, M. , Yao, Y. F. , Yao, J. , and Marchant, D. R. , 2016, “ DES Study of Blade Trailing Edge Cutback Cooling Performance With Various Lip Thicknesses,” Appl. Therm. Eng., 99, pp. 434–445. [CrossRef]
Schneider, H. , von Terzi, D. , and Bauer, H.-J. , 2010, “ Large-Eddy Simulations of Trailing-Edge Cutback Film Cooling at Low Blowing Ratio,” Int. J. Heat Fluid Flow, 31(5), pp. 767–775. [CrossRef]
Schneider, H. , von Terzi, D. , and Bauer, H.-J. , 2012, “ Turbulent Heat Transfer and Coherent Structures in Trailing-Edge Cutback Film Cooling,” Flow Turbul. Combust., 88(1–2), pp. 101–120. [CrossRef]
Naqavi, I. Z. , Tucker, P. G. , and Liu, Y. , 2014, “ Large-Eddy Simulation of the Interaction of Wall Jets With External Stream,” Int. J. Heat Fluid Flow, 50, pp. 431–444. [CrossRef]
Ravelli, S. , and Barigozzi, G. , 2018, “ Stress-Blended Eddy Simulation of Coherent Unsteadiness in Pressure Side Film Cooling Applied to a First Stage Turbine Vane,” ASME J. Heat Transfer, 140(9), p. 092201. [CrossRef]
Barigozzi, G. , Armellini, A. , Mucignat, C. , and Casarsa, L. , 2012, “ Experimental Investigation of the Effects of Blowing Conditions and Mach Number on the Unsteady Behavior of Coolant Ejection Through a Trailing Edge Cutback,” Int. J. Heat Fluid Flow, 37, pp. 37–50. [CrossRef]
Barigozzi, G. , Ravelli, S. , Armellini, A. , Mucignat, C. , and Casarsa, L. , 2013, “ Effects of Injection Conditions and Mach Number on Unsteadiness Arising Within Coolant Jets Over a Pressure Side Vane Surface,” Int. J. Heat Mass Transfer, 67, pp. 1220–1230. [CrossRef]
Abdeh, H. , and Barigozzi, G. , 2018, “ A Parametric Investigation of Vane Pressure Side Cutback Film Cooling by Dual Luminophor PSP,” Int. J. Heat Fluid Flow, 69, pp. 106–116. [CrossRef]
Ravelli, S. , and Barigozzi, G. , 2014, “ Application of Unsteady Computational Fluid Dynamics Methods to Trailing Edge Cutback Film Cooling,” ASME J. Turbomach., 136(12), p. 121006. [CrossRef]
Ravelli, S. , and Barigozzi, G. , 2015, “ Modelling the Influence of Vortex Shedding on Trailing Edge Cutback Film Cooling at Different Blowing Ratios,” 11th European Conference on Turbomachinery Fluid dynamics & Thermodynamics (ETC11), Madrid, Spain, Mar. 23–27, Paper No. ETC2015-022. https://aerospace-europe.eu/media/books/ETC2015-022.pdf
Kays, W. , 1994, “ Turbulent Prandtl Number—Where Are We?,” ASME J. Heat Transfer, 116(2), pp. 284–295. [CrossRef]
Ling, J. , Elkins, C. , and Eaton, J. , 2014, “ Optimal Turbulent Schmidt Number for RANS Modeling of Trailing Edge Slot Film Cooling,” ASME J. Eng. Gas Turbines Power, 137(7), p. 072605. [CrossRef]
Ling, J. , Ryan, K. J. , Bodart, J. , and Eaton, J. K. , 2016, “ Analysis of Turbulent Scalar Flux Models for a Discrete Hole Film Cooling Flow,” ASME J. Turbomach., 138(1), p. 011006. [CrossRef]
Menter, F. R. , 2016, “ Stress-Blended Eddy Simulation (SBES)—A New Paradigm in Hybrid RANS-LES Modeling,” Symposium on Hybrid RANS-LES Methods (HRLM 2016), Strasbourg, France, Sept. 26–28, pp. 1–5.
Menter, F. R. , 2015, “ Best Practice: Scale-Resolving Simulations in ANSYS CFD,” Version 2.00, ANSYS Germany GmbH, Darmstadt, Germany, pp. 1–75, http://www.ara.bme.hu/neptun/BMEGEATME02/2015-2016-I/gyak/tb-best-practices-scale-resolving-models.pdf
Acharya, S. , Tyagi, M. , and Hoda, A. , 2001, “ Flow and Heat Transfer Predictions for Film Cooling,” Ann. N. Y. Acad. Sci., 934(1), pp. 110–125. [CrossRef] [PubMed]
Haller, G. , 2005, “ An Objective Definition of a Vortex,” J. Fluid Mech., 525, pp. 1–26. [CrossRef]
Kolář, V. , 2011, “ Brief Notes on Vortex Identification,” Eighth WSEAS International Conference on Fluid Mechanics—Eighth WSEAS International Conference on Heat and Mass Transfer (FM'11/HMT'11), Puerto Morelos, Mexico, Jan. 29–31, pp. 23–28. https://dl.acm.org/citation.cfm?id=1959564
Green, B. , 2012, Fluid Vortices, Vol. 30, Springer Science & Business Media, Vancouver, BC, Canada.

Figures

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Fig. 1

Vane and trailing edge cooling geometry (size in mm) [24]

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Fig. 2

Three-dimensional computational domain and boundary conditions, with zoomed-in view of the cutback lip

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Fig. 3

Midspan resolution of the final grid (#2) within the PS block

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Fig. 4

Steady RANS distributions of adiabatic effectiveness η at Z/Zspan = 0.33 and 0.5, for different levels of grid

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Fig. 5

Distribution of y+ at midspan (Z/Zspan = 0.5) for different levels of grid

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Fig. 6

Contours of CFL number (top) and shielding function fSBES (bottom) at midspan (Z/Zspan = 0.5)

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Fig. 7

Flow visualizations (EXP) and (CFD) SBES instantaneous predictions of normalized temperature contours θ and normalized spanwise vorticity ωz at Z/Zspan = 0.33 (left) and Z/Zspan = 0.5 (right)

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Fig. 8

Laser Doppler velocimetry (EXP) and (CFD) SBES time averaged boundary layer profiles of ((a) and (d)) streamwise velocity u, ((b) and (e)) streamwise (u′) and ((c) and (f)) wall-normal (v′) rms velocity at s/D = 3, Z/Zspan = 0.33 (row#1—top) and s/D = 14.5, Z/Zspan = 0.5 (row#2—bottom)

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Fig. 9

Stress-blended eddy simulation instantaneous predictions of normalized temperature contours θ in planes normal to the vane at s/D = 3 (top) and s/D = 14.5 (bottom)

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Fig. 10

Flow visualizations (EXP) and (CFD) SBES instantaneous predictions of normalized temperature contours θ and normalized spanwise vorticity ωz at Z/Zspan = 0.5, downstream of the slot exit

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Fig. 11

Time-averaged SBES predictions of the adiabatic effectiveness η at MFR = 1.10% (a), 1.50% (b), and 1.95% (c), together with measurements (EXP) at MFR = 1.30% (d)

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Fig. 12

Measurements (Exp.) versus steady RANS and time-averaged SBES predictions of the laterally averaged adiabatic effectiveness ηav downstream of the cooling holes (top) and along the cutback surface (bottom)

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Fig. 13

Stress-blended eddy simulation isosurface of Q = 107s−2 colored by the normalized temperature θ

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Fig. 14

Schematic to show the probe locations downstream of row#, row#2, and cutback lip

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Fig. 15

Experimental correlation between MFR and MFRholes at Ma2is = 0.2 versus simulated condition at MFR = 1.5% (CFD)

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