0
Research Papers: Gas Turbines: Combustion, Fuels, and Emissions

Minimization of Heat Load Due to Secondary Reactions in Fuel Rich Environments

[+] Author and Article Information
Andrew T. Shewhart, Jacob J. Robertson, Nathan J. Greiner, James L. Rutledge

Air Force Institute of Technology,
WPAFB, OH 45433

Marc D. Polanka

Air Force Institute of Technology,
WPAFB, OH 45433
e-mail: Marc.Polanka@afit.edu

1Corresponding author.

Contributed by the Heat Transfer Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received March 31, 2015; final manuscript received April 23, 2015; published online June 2, 2015. Editor: David Wisler. This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States. Approved for public release; distribution is unlimited.

J. Eng. Gas Turbines Power 137(12), 121504 (Jun 02, 2015) (10 pages) Paper No: GTP-15-1114; doi: 10.1115/1.4030520 History: Received March 31, 2015

The demand for increased thrust, higher engine efficiency, and reduced fuel consumption has increased the turbine inlet temperature and pressure in modern gas turbine engines. The outcome of these higher temperatures and pressures is the potential for unconsumed radical species to enter the turbine. Because modern cooling schemes for turbine blades involve injecting cool, oxygen-rich air adjacent to the surface, the potential for reaction with radicals in the mainstream flow, and augmented heat transfer to the blade arises. This result is contrary to the purpose of film cooling. In this environment, there is a competing desire to consume any free radicals prior to the flow entering the rotor stage while still maintaining surface temperatures below the metal melting temperature. This study evaluated various configurations of multiple cylindrical rows of cooling holes in terms of both heat release and effective downstream cooling. Results were evaluated based on net heat flux reduction (NHFR) and a new wall absorption (WA) parameter which combined the additional heat available from these secondary reactions with the length of the resulting flame to determine which schemes protected the wall more efficiently. Two particular schemes showed promise. The two row upstream configuration reduced the overall augmentation of heat by creating a short, concentrated reaction area. Conversely, the roll forward configuration minimized the local heat flux enhancement by spreading the reaction area over the surface being cooled.

Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Bogard, D. G. , and Thole, K. A. , 2006, “Gas Turbine Film Cooling,” J. Propul. Power, 22(2), pp. 249–270. [CrossRef]
Bohan, B. T. , Blunck, D. L. , Kostka, S. , Jiang, N. , Roy, S. , Polanka, M. D. , and Stouffer, S. D. , 2013, “Impact of and Upstream Film-Cooling Row on Mitigation of Secondary Combustion in a Fuel Rich Environment,” ASME J. Turbomach., 136(3), p. 031008. [CrossRef]
Kirk, D. , Guenette, G. , Lukachko, S. , and Waitz, I. , 2003, “Gas Turbine Engine Durability Impacts of High Fuel–Air Ratio Combustors—Part II: Near-Wall Reaction Effects on Film-Cooled Heat Transfer,” ASME J. Eng. Gas Turbines Power, 125(3), pp. 751–759. [CrossRef]
Lukachko, S. , Kirk, D. , and Waitz, I. , 2003, “Gas Turbine Engine Durability Impacts of High Fuel–Air Ratio Combustors—Part I: Potential for Secondary Combustion of Partially Reacted Fuel,” ASME J. Eng. Gas Turbines Power, 125(3), pp. 742–750. [CrossRef]
DeLallo, M. R. , Polanka, M. D. , and Blunck, D. L. , 2012, “Impact of Trench and Ramp Film Cooling Designs to Reduce Heat Release Effects in a Reacting Flow,” ASME Paper No. GT2012-68311.
Anderson, W. S. , Evans, D. S. , Justinger, G. R. , Polanka, M. D. , Stouffer, S. D. , and Zelina, J. , 2010, “Effects of a Reacting Cross-Stream on Turbine Film Cooling,” ASME J. Eng. Gas Turbines Power, 132(5), p. 051501. [CrossRef]
Andrews, G. E. , Asere, A. A. , Gupta, M. L. , and Mkpadi, M. C. , 1990, “Effusion Cooling: The Influence of Number of Holes,” Proc. Inst. Mech. Eng., Part A, 204(3), pp. 175–182. [CrossRef]
Kakade, V. U. , Thorpe, S. J. , and Gerendás, M. , 2012, “Effusion-Cooling Performance at Gas Turbine Combustor Representative Flow Conditions,” ASME Paper No. GT2012-68115.
Nenniger, J. E. , Kridiotis, A. , Chomiak, J. , Longwell, J. P. , and Sarofim, A. F. , 1984, “Characterization of a Toroidal Well Stirred Reactor,” Symp. (Int.) Combust., 20(1), pp. 473–479.
Stouffer, S. , Pawlik, R. , Justinger, G. , Heyne, L. , Zelina, J. , and Ballal, D. , 2007, “Combustion Performance and Emissions Characteristics for a Well-Stirred Reactor for Low Volatility Hydrocarbon Fuels,” AIAA Paper No. 2007-5663.
Oguntade, H. I. , Andrews, G. E. , Burns, A. D. , Inham, D. B. , and Pourkashanian, M. , 2012, “Conjugate Heat Transfer Predictions of Effusion Cooling: The Influence of the Coolant Jet-Flow Direction on the Cooling Effectiveness,” ASME Paper No. GT2012-68517.
Moffat, R. J. , 1988, “Describing the Uncertainties in Experimental Results,” Exp. Therm. Fluid Sci., 1(1), pp. 3–17. [CrossRef]
Greiner, N. J. , Polanka, M. D. , Robertson, J. R. , and Rutledge, J. L. , 2013, “Effect of Variable Properties Within a Reacting Boundary Layer With Film Cooling,” ASME J. Eng. Gas Turbines Power, 136(5), p. 052604.

Figures

Grahic Jump Location
Fig. 1

Experimental setup for acquiring heat flux measurements of reacting film-cooling air

Grahic Jump Location
Fig. 2

Details of test section

Grahic Jump Location
Fig. 3

Heat transfer thermocouple pairs locations

Grahic Jump Location
Fig. 4

Film-cooling geometries (millimeters)

Grahic Jump Location
Fig. 5

Single row—heat flux versus blowing ratio, x/D = 17 and φ = 1.175

Grahic Jump Location
Fig. 6

Wall temperature effects on augmentation

Grahic Jump Location
Fig. 7

Single row—augmentation versus blowing ratio, φ = 1.175

Grahic Jump Location
Fig. 8

Single row—enhanced flame image, φ = 1.175 and M = 2.0

Grahic Jump Location
Fig. 9

Single row—augmentation versus equivalence ratio: solid symbols are for M = 1 and open symbols represent M = 2

Grahic Jump Location
Fig. 10

Five row—augmentation versus blowing ratio, ϕ = 1.175

Grahic Jump Location
Fig. 11

Five row—enhanced flame image, φ = 1.175 and M = 2.0

Grahic Jump Location
Fig. 12

Five row—air cooled emissions span, φ = 1.175 and M = 2.0

Grahic Jump Location
Fig. 13

Five row—augmentation versus φ, M = 2.0

Grahic Jump Location
Fig. 14

Configuration comparison—augmentation versus blowing ratio at x/D = 22 and φ = 1.175

Grahic Jump Location
Fig. 15

Configuration comparison—augmentation versus downstream distance, φ = 1.175 and M = 2.0

Grahic Jump Location
Fig. 16

Configuration comparison—augmentation versus φ at x/D = 22 and M = 2.0

Grahic Jump Location
Fig. 17

Enhanced flame images comparison, φ = 1.175 and M = 2.0. (a) Single row, (b) five row, (c) roll forward, and (d) two row upstream.

Grahic Jump Location
Fig. 18

Configuration comparison—% volume of CO, air cooling, φ = 1.175 and M = 2.0

Grahic Jump Location
Fig. 19

Configuration comparison—NHFR—nitrogen as coolant, x/D = 17

Grahic Jump Location
Fig. 20

Configuration comparison—NHFR—air as coolant, x/D = 17

Tables

Errata

Discussions

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