Spray Flame Study Using a Model Gas Turbine Swirl Burner

A model gas turbine burner was employed to investigate spray flames established under globally lean, continuous, swirling conditions. Two types of fuel were used to generate liquid spray flames: palm biodiesel and Jet-A1. The main swirling air flow was preheated to 350 °C prior to mixing with airblast-atomized fuel droplets at atmospheric pressure. The global flame structure of flame and flow field were investigated at the fixed power output of 6 kW. Flame chemiluminescence imaging technique was employed to investigate the flame reaction zones, while particle imaging velocimetry (PIV) was utilized to measure the flow field within the combustor. The flow fields of both flames are almost identical despite some differences in the flame reaction zones.

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Observation of Microexplosions in Spray Flames of Light Oil-Water Emulsions (3rd Report, Influence of the Diameter of Dispersed Water Droplets on the Spray Flame Structure)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B ◽

10.1299/kikaib.74.1649 ◽

2008 ◽

Vol 74 (743) ◽

pp. 1649-1654 ◽

Cited By ~ 6

Author(s):

Shuko TAKEDA ◽

Manabu FUCHIHATA ◽

Tamio IDA

Keyword(s):

Flame Structure ◽

Water Droplets ◽

Spray Flame ◽

Spray Flames ◽

Light Oil ◽

Oil Water

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Flow Field Derived Equivalent Reactor Networks for Accurate Chemistry Simulation in Gas Turbine Combustors

Volume 2: Combustion, Fuels and Emissions ◽

10.1115/gt2009-59861 ◽

2009 ◽

Author(s):

Scott A. Drennan ◽

Chen-Pang Chou ◽

Anthony F. Shelburn ◽

Devin W. Hodgson ◽

Cheng Wang ◽

...

Keyword(s):

Flow Field ◽

Gas Turbine ◽

Flame Structure ◽

Cost Effective ◽

Fuel Injector ◽

Accurate Analysis ◽

Detailed Chemistry ◽

Reactor Networks ◽

Detailed Kinetics ◽

Time Required

A method has been developed in which the flow field predicted by Computational Fluid Dynamics (CFD) is automatically condensed into an Equivalent Reactor Network (ERN), composed of well stirred reactors, allowing rapid and accurate analysis of emissions. This paper presents the effectiveness of utilizing an ERN that is a direct abstraction of the computational flow field for combustion analysis. The CFD results are divided into reactors using various filters on flow-field variables to construct an ERN that represents the 3-D combustor flow field and flame structure. Detailed kinetics can then be used in ERN simulations to analyze effects of fuel composition and operating condition on emissions. The technique is applied to a commercial industrial gas turbine combustor fuel injector and compared against experimental emissions results. Sensitivity of emissions predictions to different parameters in the network extraction is also presented. Parameter variations in fuel flow rate are applied to the ERN to obtain relative impacts of fuel-air ratio on the emissions of NOx without requiring new CFD solutions. This automatic approach has been found to reduce the time required to construct and analyze flow field derived ERNs with detailed chemistry by 90%. A local calculation of Damko¨hler number, important for stability analysis, is also presented. This calculation also uses abstracted information from the CFD flow field and detailed-kinetics simulations for more accurate, cost-effective analysis.

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Unsteady flame and flow field interaction of a premixed model gas turbine burner

Proceedings of the Combustion Institute ◽

10.1016/j.proci.2006.07.081 ◽

2007 ◽

Vol 31 (2) ◽

pp. 3197-3205 ◽

Cited By ~ 17

Author(s):

K.-U. Schildmacher ◽

A. Hoffmann ◽

L. Selle ◽

R. Koch ◽

C. Schulz ◽

...

Keyword(s):

Flow Field ◽

Gas Turbine ◽

Field Interaction ◽

Unsteady Flame ◽

Gas Turbine Burner

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Comparison of the Combustion Characteristics of Liquid Single-Component Fuels in a Gas Turbine Model Combustor

Volume 4A: Combustion, Fuels and Emissions ◽

10.1115/gt2016-56177 ◽

2016 ◽

Cited By ~ 5

Author(s):

Jasper Grohmann ◽

William O’Loughlin ◽

Wolfgang Meier ◽

Manfred Aigner

Keyword(s):

Gas Turbine ◽

Alternative Fuels ◽

Numerical Models ◽

Flame Structure ◽

Mie Scattering ◽

Single Component ◽

Liquid Fuels ◽

Reacting Flow ◽

Spray Flames ◽

Turbine Model

Alternative production pathways for liquid fuels provide the opportunity to adjust the chemical composition of the product in order to improve combustion performance. In this study, flame characteristics of selected single-component fuels were investigated to provide a basis for a better understanding of the influence of specific fuel components on the combustion behaviour. The measurements were performed in a redesigned gas turbine model combustor for swirl-stabilised spray flames under atmospheric pressure. The combustor features a dual-swirl geometry and a prefilming airblast atomiser. The combustion chamber provides good optical access and yields well-defined boundary conditions. As part of different projects in the field of alternative fuels, two liquid single-component fuels (n-hexane, n-dodecane) and kerosene Jet A-1 were investigated. Flow fields of the nonreacting and reacting flow were measured using stereo particle image velocimetry. The flame structure and spray distribution were derived from CH* chemiluminescence and Mie scattering respectively. Lean blowout limits were measured. Results show noticeable differences in combustion behaviour of the chosen fuels at comparable flow conditions. Furthermore, the results provide a detailed data base for the validation of numerical models.

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Flow Field and Combustion Characterization of Premixed Gas Turbine Flames by Planar Laser Techniques

Volume 3: Combustion, Fuels and Emissions, Parts A and B ◽

10.1115/gt2008-50520 ◽

2008 ◽

Cited By ~ 3

Author(s):

Ulrich Stopper ◽

Manfred Aigner ◽

Wolfgang Meier ◽

Rajesh Sadanandan ◽

Michael Sto¨hr ◽

...

Keyword(s):

Flow Field ◽

Gas Turbine ◽

Shear Layers ◽

Diagnostic Methods ◽

Single Shot ◽

Mean Flow ◽

Planar Laser ◽

Primary Reactions ◽

Reaction Zones ◽

Industrial Gas Turbine

Lean premixed natural gas/air flames produced by an industrial gas turbine burner were analyzed using laser diagnostic methods. For this purpose, the burner was equipped with an optical combustion chamber and operated with preheated air at various thermal powers P, equivalence ratios Φ, and pressures up to p = 6 bar. For the visualization of the flame emissions OH* chemiluminescence imaging was applied. Absolute flow velocities were measured using particle image velocimetry (PIV), and the reaction zones as well as regions of burnt gas were characterized by planar laser induced fluorescence (PLIF) of OH. Using these techniques, the combustion behavior was characterized in detail. The mean flow field could be divided into different regimes: the inflow, a central and an outer recirculation zone, and the outgoing exhaust flow. Single-shot PIV images demonstrated that the instantaneous flow field was composed of small and medium sized vortices, mainly located along the shear layers. The chemiluminescence images reflected the regions of heat release. From the PLIF images it was seen that the primary reactions are located in the shear layers between the inflow and the recirculation zones and that the appearance of the reaction zones changed with flame parameters.

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Theory of Stagnation-Point Spray Flame Ignition

Proceedings ILASS–Europe 2017. 28th Conference on Liquid Atomization and Spray Systems ◽

10.4995/ilass2017.2017.4643 ◽

2017 ◽

Author(s):

J. Barry Greenberg ◽

Gershon Kats

Keyword(s):

Flow Field ◽

Small Parameter ◽

Stagnation Point ◽

Fuel Spray ◽

Asymptotic Approach ◽

Fuel Droplets ◽

Spray Flame ◽

Flame Ignition ◽

Hot Surface ◽

First Time

A theory of stagnation-point spray flame ignition by an isothermal hot surface is presented for the first time. A mixture of fuel droplets and air flowing against an isothermal hot surface (such as a hot ignition probe) is considered. The spray of droplets is modelled using the sectional approach and a mono-sectional case is adopted for simplicity. A single global chemical reaction is assumed for the case when ignition occurs. The mathematical analysis makes use of a small parameter that is exploited for an asymptotic approach. The analysis produces a criterion for ignition that includes effects of the flow field, the reactants and the fuel spray-related parameters. Numerical computations reveal the way in which the latter impact on whether ignition will occur or not.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4643

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Flame and Spray Dynamics During the Light-Round Process in an Annular System Equipped With Multiple Swirl Spray Injectors

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4042024 ◽

2019 ◽

Vol 141 (6) ◽

Cited By ~ 2

Author(s):

Kevin Prieur ◽

Guillaume Vignat ◽

Daniel Durox ◽

Thierry Schuller ◽

Sébastien Candel

Keyword(s):

Flame Front ◽

Flame Structure ◽

Axial Direction ◽

Azimuthal Direction ◽

Time Resolved ◽

Fuel Droplets ◽

Spray Flames ◽

Annular Combustor ◽

Swirling Flame ◽

Injection Unit

A successful ignition in an annular multi-injector combustor follows a sequence of steps. The first injector is ignited; two arch-shaped flame branches nearly perpendicular to the combustor backplane form; they propagate, igniting each injection unit; they merge. In this paper, characterization of the propagation phase is performed in an annular combustor with spray flames fed with liquid n-hepane. The velocity and the direction of the arch-like flame branch are investigated. Near the backplane, the flame is moving in a purely azimuthal direction. Higher up in the chamber, it is also moving in the axial direction due to the volumetric expansion of the burnt gases. Time-resolved particle image velocimetry (PIV) measurements are used to investigate the evaporating fuel droplets dynamics. A new result is that, during the light-round, the incoming flame front pushes the fuel droplets in the azimuthal direction well before its leading point. This leads to a decrease in the local droplet concentration and local mixture composition over not yet lit injectors. For the first time, the behavior of an individual injector ignited by the passing flame front is examined. The swirling flame structure formed by each injection unit evolves in time. From the ignition of an individual injector to the stabilization of its flame in its final shape, approximately 50 ms elapse. After the passage of the traveling flame, the newly ignited flame flashbacks into the injector during a few milliseconds, for example, 5 ms for the conditions that are tested. This could be detrimental to the service life of the unit. Then, the flame exits from the injection unit, and its external branch detaches under the action of cooled burnt gases in the outer recirculation zone (ORZ).

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Flow Field and Combustion Characterization of Premixed Gas Turbine Flames by Planar Laser Techniques

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2969093 ◽

2008 ◽

Vol 131 (2) ◽

Cited By ~ 36

Author(s):

Ulrich Stopper ◽

Manfred Aigner ◽

Wolfgang Meier ◽

Rajesh Sadanandan ◽

Michael Stöhr ◽

...

Keyword(s):

Flow Field ◽

Gas Turbine ◽

Shear Layers ◽

Diagnostic Methods ◽

Single Shot ◽

Mean Flow ◽

Planar Laser ◽

Primary Reactions ◽

Reaction Zones ◽

Industrial Gas Turbine

Lean premixed natural gas/air flames produced by an industrial gas turbine burner were analyzed using laser diagnostic methods. For this purpose, the burner was equipped with an optical combustion chamber and operated with preheated air at various thermal powers P, equivalence ratios Φ, and pressures up to p=6 bars. For the visualization of the flame emissions OH∗ chemiluminescence imaging was applied. Absolute flow velocities were measured using particle image velocimetry (PIV), and the reaction zones as well as regions of burnt gas were characterized by planar laser-induced fluorescence (PLIF) of OH. Using these techniques, the combustion behavior was characterized in detail. The mean flow field could be divided into different regimes: the inflow, a central and an outer recirculation zone, and the outgoing exhaust flow. Single-shot PIV images demonstrated that the instantaneous flow field was composed of small and medium sized vortices, mainly located along the shear layers. The chemiluminescence images reflected the regions of heat release. From the PLIF images it was seen that the primary reactions are located in the shear layers between the inflow and the recirculation zones and that the appearance of the reaction zones changed with flame parameters.

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