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

Different Flame Patterns Linked With Swirling Injector Interactions in an Annular Combustor

[+] Author and Article Information
Daniel Durox

Laboratoire EM2C,
CNRS,
CentraleSupélec,
Université Paris-Saclay,
Grande voie des vignes,
Châtenay-Malabry cedex 92295, France
e-mail: daniel.durox@centralesupelec.fr

Kevin Prieur

Laboratoire EM2C,
CNRS,
CentraleSupélec,
Université Paris-Saclay,
Grande voie des vignes,
Châtenay-Malabry cedex 92295, France;
Safran Tech,
E&P,
Rue des Jeunes Bois,
Châteaufort, CS 80112,
Magny-Les-Hameaux 78772, France

Thierry Schuller, Sébastien Candel

Laboratoire EM2C,
CNRS,
CentraleSupélec,
Université Paris-Saclay,
Grande voie des vignes,
Châtenay-Malabry cedex 92295, France

1Corresponding author.

Contributed by the Combustion and Fuels Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received February 27, 2016; final manuscript received March 30, 2016; published online April 26, 2016. Editor: David Wisler.

J. Eng. Gas Turbines Power 138(10), 101504 (Apr 26, 2016) (8 pages) Paper No: GTP-16-1093; doi: 10.1115/1.4033330 History: Received February 27, 2016; Revised March 30, 2016

Experiments in cold and reactive conditions carried out in linear arrays of injectors indicate that the flows established by neighboring injectors exhibit alternating patterns if the distance between two injectors is too small (see, for example, ASME-GT2013-94280, GT2014-25094, and GT2015-42509). This issue is investigated in this article by making use of a recently developed annular combustion chamber (ACC). This device designated as MICCA is equipped with multiple swirling injectors and its side walls are made of quartz providing full optical access to the flame region, thus allowing detailed studies of the combustion region structure and dynamics. Experiments reported in this article rely on direct observations of the flame region through light emission imaging using two standard cameras and an intensified high-speed CMOS camera. The data gathered indicate that interactions between successive injectors give rise to patterns of flames which exhibit an alternate geometry where one flame has a relatively low expansion angle while the next spreads sideways. This pattern is then repeated with a period which corresponds to twice the injector spacing. Such arrangements arise when the angle of the cup used as the end-piece of each injector exceeds a critical value. The effects of mass flow rate, equivalence ratio, and injector offset are also investigated. It is shown that the angle which defines the cup opening is the main control parameter. It is also found that when this angle exceeds a certain value and when the laminar burning velocity is fast enough, the flame pattern switches in an unsteady manner between two possible configurations. It is shown that these alternating flame patterns lead to alternating heat release rate distributions and inhomogeneous heat transfer to the chamber walls featuring a helicoidal pattern. Conditions leading to alternating flame patterns are finally discussed by making use of a recent flow regime diagram.

FIGURES IN THIS ARTICLE
<>
Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

View of the ACC. The mean diameter of the ring is 350 mm. The walls are 200 mm in length. The injectors are equipped with cups with an angle of 90 deg in this case.

Grahic Jump Location
Fig. 2

View of the swirler. The six holes are 3 mm in diameter.

Grahic Jump Location
Fig. 3

The different injectors with and without cups. The offset is measured with respect to the combustion chamber backplane. D corresponds to the outlet diameter of the cups.

Grahic Jump Location
Fig. 4

Axial and azimuthal velocities profiles, Uz and Uθ. These profiles are measured by laser Doppler velocimetry, at 1.7 mm downstream of the outlet of a single injector. There is no cup, like in Fig. 3, at the top left. For this test, the mean flow rate is Ub=17.1 m s−1. The flow is confined by a cylindrical tube, 50 mm in diameter and 200 mm in length.

Grahic Jump Location
Fig. 5

Typical flame shapes obtained for the different injector geometries. Ub = 17.1 m s − 1 and ϕ=0.74.

Grahic Jump Location
Fig. 6

Influence of the bulk velocity on the flame topology. The left column corresponds to a 70 deg cup, and the right column pertains to a 105 deg cup. ϕ= 0.74. From the top to the bottom rows: Ub=12.2, 17.1, and 22 m s−1, respectively.

Grahic Jump Location
Fig. 7

Influence of the equivalence ratio on the flame topology for 90 deg cup. Ub≃17.1 m s−1. Two cameras are positioned near the combustion chamber, with two different viewing angles. From the top to the bottom rows: ϕ= 0.64, 0.74, 0.84, and 0.94.

Grahic Jump Location
Fig. 8

105 deg cup: Ub≃17.3 m s−1 and ϕ= 0.94. Instability at low frequency of the flame patterns.

Grahic Jump Location
Fig. 9

Time evolution of the light intensity for flames A and B defined in Fig. 8

Grahic Jump Location
Fig. 10

For 90 deg cup: Ub≃14.7 m s−1 and ϕ= 0.74. The first two images show light emission from the two types of flames: the V-type flame and the M-type flared flame. The result of an Abel inversion of the two flames is shown in the last two images.

Grahic Jump Location
Fig. 11

Visualization of the thermal effects for 90 deg cup. Ub≈17.1 m s−1.

Grahic Jump Location
Fig. 12

Operating map introduced by Fanaca et al. [15]. The present data are plotted on this map in red squares located at a swirl number S = 0.71. For the injectors without cup, the ratio AccAbu is equal to 43.8 and lies outside this graph.

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