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

A New Spin on Small-Scale Combustor Geometry

[+] Author and Article Information
Brian T. Bohan

Air Force Institute of Technology,
Wright-Patterson AFB, OH 45433
e-mail: Brian.Bohan@afit.edu

Marc D. Polanka

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

Contributed by the Combustion and Fuels Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received May 25, 2018; final manuscript received June 6, 2018; published online December 4, 2018. 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 141(1), 011504 (Dec 04, 2018) (10 pages) Paper No: GTP-18-1227; doi: 10.1115/1.4040658 History: Received May 25, 2018; Revised June 06, 2018

The ultra-compact combustor (UCC) is an innovative combustor system alternative to traditional turbine engine combustors with the potential for engine efficiency improvements with a reduced volume. Historically, the UCC cavity had been configured such that highly centrifugally loaded combustion took place in a recessed circumferential cavity positioned around the outside diameter (OD) of the engine. One of the obstacles with this design was that the combustion products had to migrate radially across the span of a vane while being pushed downstream by a central core flow. This configuration proved difficult to produce a uniform temperature distribution at the first turbine rotor. The present study has taken a different spin on the implementation of circumferential combustion. Namely, it aims to combine the combustion and space saving benefits of the highly centrifugally loaded combustion of the UCC in a new combustor orientation that places the combustor axially upstream of the turbine versus radially outboard. An iterative design approach was used to computationally analyze this new geometry configuration with the goal of fitting within the casing of a JetCat P90RXi. This investigation revealed techniques for implementation of this concept including small-scale combustor centrifugal air loading development, maintaining combustor circumferential swirl, combustion stability, and fuel distribution are reported. The final combustor configuration was manufactured and experimentally tested, validating the computational results. Furthermore, dramatic improvements in the uniformity of the turbine inlet temperature profiles are revealed over historical UCC concepts.

Copyright © 2019 by ASME
Your Session has timed out. Please sign back in to continue.

References

Lewis, G. D. , 1973, “ Swirling Flow Combustion—Fundamentals and Application,” AIAA Paper No. 73-1250.
Briones, A. M. , Sekar, B. , and Erdmann, T. J. , 2015, “ Effect of Centrifugal Force on Turbulent Premixed Flames,” ASME J. Eng. Gas Turbines Power, 137(1), p. 011501. [CrossRef]
Conrad, M. M. , 2013, “ Integration of an Inter Turbine Burner to a Jet Turbine Engine,” M.S. thesis, Air Force Institute of Technology, WPAFB, OH. http://www.dtic.mil/docs/citations/ADA582663
Cottle, A. E. , and Polanka, M. D. , 2015, “ Optimization of Ultra Compact Combustor Flow Path Splits,” AIAA Paper No. AIAA-2015-0100.
Bohan, B. T. , Polanka, M. D. , and Goss, L. P. , 2017, “ Development and Testing of a Variable Geometry Diffuser in an Ultra-Compact Combustor,” AIAA Paper No. AIAA-2017-0777.
DeMarco, K. J. , Bohan, B. T. , Hornedo, E. A. , Polanka, M. D. , and Goss, L. P. , 2018, “ Design Strategy for Fuel Introduction to a Circumferential Combustion Cavity,” AIAA Paper No. AIAA-2018-1876.
Yonezawa, Y. , Toh, H. , Goto, S. , and Obata, M. , 1990, “ Development of the Jet-Swirl High Loading Combustor,” AIAA Paper No. AIAA-90-2451.
Samuelsen, S. , 2006, “ Conventional Type Combustion,” The Gas Turbine Handbook, U.S. Department of Energy, Office of Fossil Energy, National Energy Technology Laboratory (NETL), Morgantown, WV, Report No. DOE/NETL-2006-1230.
Barringer, M. D. , Thole, K. A. , and Polanka, M. D. , 2009, “ Effects of Combustor Exit Profiles on High Pressure Turbine Vane Aerodynamics and Heat Transfer,” ASME J. Turbomach., 131(2), p. 021008. [CrossRef]
Mattingly, J. D. , 2006, Elements of Propulsion: Gas Turbines and Rockets, American Institute of Aeronautics and Astronautics, Reston, VA, pp. 765–766.
Bohan, B. T. , and Polanka, M. D. , 2013, “ Analysis of Flow Migration in an Ultra-Compact Combustor,” ASME J. Eng. Gas Turbines Power, 135(5), p. 051502. [CrossRef]
Damele, C. J. , Polanka, M. D. , Wilson, J. D. , and Rutledge, J. L. , 2014, “ Characterizing Thermal Exit Conditions for an Ultra Compact Combustor,” AIAA Paper No. AIAA-2014-0456.
Lebay, K. D. , Polanka, M. D. , and Branam, R. , 2011, “ Characterizing the Effect of Radial Vane Height on Flame Migration in an Ultra Compact Combustor,” ASME Paper No. GT 2011-45919.
Gilbert, N. A. , Cottle, A. E. , Polanka, M. D. , and Goss, L. P. , 2016, “ Enhancing Flow Migration and Reducing Emissions in Full Annular Ultra Compact Combustor,” AIAA Paper No. AIAA-2016-2122.
Cottle, A. E. , Gilbert, N. A. , and Polanka, M. D. , 2016, “ Mechanisms for Enhanced Flow Migration From an Annular, High-g Ultra Compact Combustor,” AIAA Paper No. AIAA-2016-1392.
Cottle, A. E. , 2016, “ Flow Field Dynamics in a High-g Ultra-Compact Combustor,” Ph.D. thesis, Air Force Institute of Technology, WPAFB, OH. http://www.dtic.mil/docs/citations/AD1032042
Hornedo, E. A. , Bohan, B. T. , Cottle, A. E. , Schmiedel, C. , Polanka, M. D. , and Goss, L. P. , 2017, “ Design Strategy for Product Migration From a Circumferential Combustion Cavity,” AIAA Paper No. AIAA-2017-0390.
Briones, A. M. , Burrus, D. L. , Erdmann, T. J. , and Shouse, D. T. , 2015, “ Effect of Centrifugal Force on the Performance of High-g Ultra Compact Combustor,” ASME Paper No. GT 2015-43445.
Cottle, A. E. , and Polanka, M. D. , 2016, “ Numerical and Experimental Results From a Common-Source High-g Ultra-Compact Combustor,” ASME Paper No. GT 2016-56215.
ANSYS, 2016, FLUENT 16.2 User's Guide, ANSYS, Inc., Canonsburg, PA.
Zelina, J. , Sturgess, G. J. , and Shouse, D. T. , 2004, “ The Behavior of an Ultra-Compact Combustor (Ucc) Based on Centrifugally-Enhanced Turbulent Burning Rates,” AIAA Paper No. 2004-3541.
Young, D. F. , Munson, B. R. , and Okiishi, T. H. , 2004, A Brief Introduction to Fluid Mechanics, 3rd ed., Wiley, Hoboken, NJ, pp. 83–84.
Lapsa, A. P. , and Dahm, W. J. , 2009, “ Hyperacceleration Effects on Turbulent Combustion in Premixed Step-Stabilized Flames,” Proc. Combust. Inst., 32(2), pp. 1731–1738. [CrossRef]
Turns, S. R. , 1996, An Introduction to Combustion, 2nd ed., McGraw-Hill, New York.

Figures

Grahic Jump Location
Fig. 1

AFIT Version 3 Ultra Compact Combustor with variable geometry diffuser and stepped circumferential cavity OD wall

Grahic Jump Location
Fig. 2

JetCat P90RXi cross section with fluid flow path

Grahic Jump Location
Fig. 3

JetCat P90RXi cross section with Configuration 6 combustor installed and compared to the stock combustor

Grahic Jump Location
Fig. 4

Combustor type 1, single chamber (C2 shown)

Grahic Jump Location
Fig. 7

Configuration 1 grid independence check test locations on 30 deg sector domain

Grahic Jump Location
Fig. 5

Combustor type 2, dual chamber (C6 shown)

Grahic Jump Location
Fig. 6

Computational domain for Configuration 6 with boundary conditions labeled

Grahic Jump Location
Fig. 16

Comparison of single versus dual chamber combustors

Grahic Jump Location
Fig. 10

Fuel distribution in the stabilizing backward-facing steps (Results from C2). Colored by propane mass fraction

Grahic Jump Location
Fig. 11

Fuel distribution in the stabilizing backward-facing steps with fences (Results from C3). Colored by propane mass fraction.

Grahic Jump Location
Fig. 12

Fuel distribution in backward-facing steps on the combustor forward wall (Results from C4). Colored by propane mass fraction.

Grahic Jump Location
Fig. 13

Configuration 5 cross section with secondary/dilution air inlet holes labeled by blue arrows

Grahic Jump Location
Fig. 14

Secondary/dilution air layering. Temperature contours on periodic walls of combustor C4.

Grahic Jump Location
Fig. 15

Circumferentially averaged temperatures on the combustor exit plane for all configurations

Grahic Jump Location
Fig. 8

Backward-facing steps for combustion stability

Grahic Jump Location
Fig. 9

Temperature contours (K) showing flames anchored to steps (Results from C6)

Grahic Jump Location
Fig. 17

Temperature contours (K) in dual chamber Combustor Configuration 6

Grahic Jump Location
Fig. 18

Temperature contours (K) in Combustor Configuration 7 with primary zone exit diffuser and larger secondary/dilution zone volume

Grahic Jump Location
Fig. 19

Contours of velocity angle (deg) on the combustor exit plane of Configuration 5 and circumferentially averaged velocity angles from Configurations 5, 6, and 7

Grahic Jump Location
Fig. 21

Configuration 7 experimentally combusting at a global equivalence ratio of 0.31

Grahic Jump Location
Fig. 22

Configuration 7 experimentally derived exit temperature contours at a global equivalence ratio of 0.31

Grahic Jump Location
Fig. 20

Configuration 7 experimental hardware mated to stock JetCat P90RXi components

Tables

Errata

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