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

Analysis of Flow Migration in an Ultra-Compact Combustor

[+] Author and Article Information
Brian T. Bohan

Deputy Branch Chief High and Low Speed Aerodynamic Configuration Branches,
Air Vehicles Directorate,
Air Force Research Laboratory,
Wright-Patterson AFB, OH 45433

Marc D. Polanka

Associate Professor
Department of Aeronautical and Astronautical Engineering,
Air Force Institute of Technology,
Wright-Patterson AFB, OH 45433

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the Journal of Engineering for Gas Turbines and Power. Manuscript received September 13, 2011; final manuscript received August 24, 2012; published online April 23, 2013. Editor: Dilip R. Ballal.

J. Eng. Gas Turbines Power 135(5), 051502 (Apr 23, 2013) (11 pages) Paper No: GTP-11-1312; doi: 10.1115/1.4007866 History: Received September 13, 2011; Revised August 24, 2012

The ultra-compact combustor (UCC) has the potential to offer improved thrust-to-weight and overall efficiency in a turbojet engine. The thrust-to-weight improvement is due to a reduction in engine weight by shortening the combustor section through the use of the revolutionary circumferential combustor design. The improved efficiency is achieved by using an increased fuel-to-air mass ratio and allowing the fuel to fully combust prior to exiting the UCC system. Furthermore, g-loaded combustion offers increased flame speeds that can lead to smaller combustion volumes. One of the issues with the UCC is that the circumferential combustion of the fuel results in hot gases present at the outside diameter of the core flow. These hot gases need to migrate radially from the circumferential cavity and blend with the core flow to present a uniform temperature distribution to the high-pressure turbine rotor. The current research focused on correlations to control the UCC cavity velocity, control the temperature profile throughout the UCC section, analyze the exhaust species exiting the combustor, and quantify pressure losses in the system. To achieve these goals, a computational fluid dynamics (CFD) analysis was used on a UCC geometry scaled to a representative fighter-scale engine. The analysis included a study of cavity to core flow interaction characteristics, a 5- and 12-species combustion model of liquid and gaseous fuel, and determination of species exiting the combustor. Computational comparisons were also made between an engine realistic condition and an ambient pressure rig environment.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.


Mattingly, J. D., Heiser, W. H., and Daley, D. H., 1987, Aircraft Engine Design, AIAA, Washington, DC.
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.
Zelina, J., Shouse, D. T., and Hancock, R. D., 2004, “Ultra-Compact Combustors for Advanced Gas Turbine Engines,” Proceedings of ASME Turbo Expo (GT2004), Vienna, Austria, June 14–17, ASME Paper No. GT2004-53155. [CrossRef]
Lewis, G. D., 1973, “Swirling Flow Combustion—Fundamentals and Application,” Presented at AIAA/SAE 9th Propulsion Conference, Las Vegas, NV, November 5–7, AIAA Paper No. 1973-1250.
Sirignano, W. A., Delplanque, J. P., and Liu, F., 1997, “Selected Challenges in Jet and Rocket Engine Combustion Research,” 33rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Seattle, WA, July 6–9, Paper No. AIAA-1997-2701.
Hermanson, K. S., and Thole, K. A., 2000, “Effects of Mach Number on Secondary Flow Characteristics,” Int. J. Turbo. Jet Engines, 17, pp. 179–196. [CrossRef]
Hermanson, K. S., and Thole, K. A., 2000, “Effects of Inlet Conditions on Endwall Secondary Flows,” J. Propul. Power, 16(2), pp. 286–296. [CrossRef]
Anisko, J. F., Anthenien, R. A., and Zelina, J., 2006, “Numerical Investigation of Cavity-Vane Interactions Within the Ultra-Compact Combustor,” 44th AIAA Aerospace Sciences Meeting and Exhibit , Reno, NV, January 9–12, Paper No. AIAA-2006-805.
Baskharone, E., 2006, Principles of Turbomachinery in Air-Breathing Engines, 1st ed., Cambridge University Press, New York.
Bohan, B., 2011, “Analysis of Flow Migration in an Ultra-Compact Combustor,” Master’s thesis, Air Force Institute of Technology, WPAFB, OH.
FLUENT, Inc., 2006. FLUENT 6.3 User’s Guide, Fluent Inc., Lebanon, NH.
LeBay, K., 2011, “Characterization of Centrifugally-Loaded Flame Migration for Ultra-Compact Combustors,” Ph.D. thesis, Air Force Institute of Technology, WPAFB, OH.
Society of Automotive Engineers, 1996, Procedure for the Analysis and Evaluation of Gaseous Emissions From Aircraft Engines, Aerospace Recommended Practice Paper No. ARP1533, Society of Automotive Engineers, Warrendale, PA.


Grahic Jump Location
Fig. 1

UCC and traditional combustor systems comparison

Grahic Jump Location
Fig. 2

UCC cavity equivalence ratio at blowout as a function of cavity g-loading [2]

Grahic Jump Location
Fig. 3

Cross-sectional view of UCC section used in the current analysis (dimensions are in centimeters)

Grahic Jump Location
Fig. 4

Origin and orientation of the hybrid vane design

Grahic Jump Location
Fig. 5

Computational domain relative to full engine annulus

Grahic Jump Location
Fig. 6

Computational domain for the 20 hybrid-vane configuration

Grahic Jump Location
Fig. 7

Computational domain for the 30 hybrid-vane configuration

Grahic Jump Location
Fig. 8

Relationship of cavity inlet velocity to cavity tangential velocity and hole diameter

Grahic Jump Location
Fig. 9

Nonreacting results from preliminary analysis with five-species reacting flow results

Grahic Jump Location
Fig. 10

Streamlines in the circumferential cavity as viewed from upstream (baseline inlet above, 3X inlet below)

Grahic Jump Location
Fig. 11

Circumferentially averaged total temperatures at combustor section exit using the 12-species model and ideal air inlet diameters with piecewise-polynomial Cp values

Grahic Jump Location
Fig. 12

Total temperature contours on UCC components for ideal tangential velocities

Grahic Jump Location
Fig. 13

Isosurfaces colored by total temperature using the 12-species combustion model and ideal air inlet diameters with a 20 hybrid vane engine configuration

Grahic Jump Location
Fig. 14

Circumferentially averaged mass fractions of species at combustor section exit with ideal air inlet diameters and a 20-vane engine configuration



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