Spray and Emission Characteristics Near Lean Blow Out in a Counter-Swirl Stabilized Gas Turbine Combustor

2006 ◽  
Author(s):  
Jonathan A. Colby ◽  
Suresh Menon ◽  
Jechiel Jagoda
Keyword(s):  
Droplet Diameter ◽  
Reacting Flow ◽  
Gas Turbine Combustor ◽  
Complete Combustion ◽  
Fuel Droplets ◽  
Phase Velocities ◽  
Fuel Jet ◽  
Key Factor ◽  
Flow Features ◽  
Initial Droplet Size

An experimental study of a single, swirl cup burner is carried out to improve understanding of the lean reacting flow field near idle conditions for an annular spray combustor. The counter-swirler is mounted horizontally in a trapezoidal cross-section combustor with quartz plate walls. Liquid fuel, Jet-A, is initially atomized using a simplex nozzle, and then a designed re-atomization occurs from the swirler hardware. Measurements of non-reacting and reacting gas phase velocities enable the direct comparison of critical flow features at various power settings. Droplet diameter and exhaust composition measurements confirm that the initial droplet size is a key factor in emission levels. Smaller droplets in the spray periphery tend to evaporate and burn premixed, while larger droplets in the spray core convect downstream and burn with a sheath-type, non-premixed flame. The presence of small fuel droplets in the spray may ensure more complete combustion and improve combustor stability at lean, low power settings.

scholarly journals Assessment of Combustor Working Environments

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Leiyong Jiang ◽  
Andrew Corber
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Reacting Flow ◽  
Gas Turbine Combustor ◽  
Two Phase ◽  
Turbine Engine ◽  
Working Environments ◽  
Flow Features ◽  
Critical Components ◽  
The Cost

In order to assess the remaining life of gas turbine critical components, it is vital to accurately define the aerothermodynamic working environments and service histories. As a part of a major multidisciplinary collaboration program, a benchmark modeling on a practical gas turbine combustor is successfully carried out, and the two-phase, steady, turbulent, compressible, reacting flow fields at both cruise and takeoff are obtained. The results show the complicated flow features inside the combustor. The airflow over each flow element of the combustor can or liner is not evenly distributed, and considerable variations, ±25%, around the average values, are observed. It is more important to note that the temperatures at the combustor can and cooling wiggle strips vary significantly, which can significantly affect fatigue life of engine critical components. The present study suggests that to develop an adequate aerothermodynamics tool, it is necessary to carry out a further systematic study, including validation of numerical results, simulations at typical engine operating conditions, and development of simple correlations between engine operating conditions and component working environments. As an ultimate goal, the cost and time of gas turbine engine fleet management must be significantly reduced.

CFD Analysis of Scramjet Combustor with Non-Premixed Turbulence Model Using Ramp Injector

2014 ◽  
Vol 555 ◽  
pp. 18-25 ◽  
Author(s):  
Krishna Murari Pandey ◽  
Sukanta Roga
Keyword(s):  
Supersonic Combustion ◽  
Maximum Temperature ◽  
Combustion Model ◽  
Inlet Temperature ◽  
Reacting Flow ◽  
Complete Combustion ◽  
Scramjet Combustor ◽  
Air Inlet ◽  
Fuel Jet ◽  
Combustion Of Hydrogen

This paper presents the supersonic combustion of hydrogen using strut injector along with two-dimensional turbulent non-premixed combustion model with air inlet temperature of 750 0k and vitiated Mach number of 2. In this process, a PDF approach is created and this method needs solution to a high dimensional PDF transport equation. As the combustion of hydrogen fuel is injected from the strut injector, it is successfully used to model the turbulent reacting flow field. It is observed from the present work that, the maximum temperature of 2096 0k occurred in the recirculation area which is produced due to shock wave-expansion and the fuel jet losses concentration and after passing successively through such areas, temperature decreased slightly along the axis. From the maximum mass fraction of OH, it is observed that there is very little amount of OH around 0.0017 were found out after combustion. By providing strut injector, expansion wave is created which causes the proper mixing between the fuel and air that results in complete combustion.

Numerical Simulations of Low-Btu Coal Gas Combustion in a Gas Turbine Combustor

1991 ◽  
Author(s):  
Ajay K. Agrawal ◽  
Tah-Teh Yang
Keyword(s):  
Gas Turbine ◽  
Mixture Fraction ◽  
Flame Temperature ◽  
Three Dimensional ◽  
Reacting Flow ◽  
Gas Temperature ◽  
Gas Turbine Combustor ◽  
Gas Combustion ◽  
Complete Combustion ◽  
Coal Gas

A numerical model for turbulent reacting flow is described and applied for predictions in an industrial gas turbine combustor operating on low-Btu coal gas. The model, based on fast-reaction limit, used Favre averaged conservation equations with the standard k-ε model of turbulence. Effects of turbulent fluctuations on chemistry are described statistically in terms of the mean, variance and probability density function (assumed to be β-distribution) of the mixture fraction. Two types of geometric approximations, namely axisymmetric and three-dimensional, were used to model the combustor. Computations were performed with (a) no swirl (b) weak swirl and (c) strong swirl at the fuel and primary air inlets. Essentially, the same bulk mean temperature distributions were obtained for axisymmetric and three-dimensional calculations while the computed pattern factors and the liner wall temperatures for the two differed significantly. Complete combustion was predicted with strong swirl, a result supported by the available test data. The maximum liner wall temperature predicted for three-dimensional calculations compared favorably with the experimental data while the predicted maximum exhaust gas temperature differed by ≈120 K. The difference was attributed to measurement uncertainties, model assumptions and lack of accurate data at the inlets. The maximum flame temperature was below 1,850 K indicating that thermal NOx may be insignificant.

Experimental investigation of isothermal and reacting flow characteristics downstream of axisymmetric bluff body stabilizers under stratified or fully premixed inlet mixture conditions

2020 ◽  
Author(s):  
Γεώργιος Πατεράκης
Keyword(s):  
Experimental Investigation ◽  
Turbulent Flow ◽  
Bluff Body ◽  
Operating Conditions ◽  
Reacting Flow ◽  
Wide Range ◽  
Flow Features ◽  
Air Mixing ◽  
The Impact ◽  
Stratified Flames

The current work describes an experimental investigation of isothermal and turbulent reacting flow field characteristics downstream of axisymmetric bluff body stabilizers under a variety of inlet mixture conditions. Fully premixed and stratified flames established downstream of this double cavity premixer/burner configuration were measured and assessed under lean and ultra-lean operating conditions. The aim of this thesis was to further comprehend the impact of stratifying the inlet fuelair mixture on the reacting wake characteristics for a range of practical stabilizers under a variety of inlet fuel-air settings. In the first part of this thesis, the isothermal mean and turbulent flow features downstream of a variety of axisymmetric baffles was initially examined. The effect of different shapes, (cone or disk), blockage ratios, (0.23 and 0.48), and rim thicknesses of these baffles was assessed. The variations of the recirculation zones, back flow velocity magnitude, annular jet ejection angles, wake development, entrainment efficiency, as well as several turbulent flow features were obtained, evaluated and appraised. Next, a comparative examination of the counterpart turbulent cold fuel-air mixing performance and characteristics of stratified against fully-premixed operation was performed for a wide range of baffle geometries and inlet mixture conditions. Scalar mixing and entrainment properties were investigated at the exit plane, at the bluff body annular shear layer, at the reattachment region and along the developing wake were investigated. These isothermal studies provided the necessary background information for clarifying the combustion properties and interpreting the trends in the counterpart turbulent reacting fields. Subsequently, for selected bluff bodies, flame structures and behavior for operation with a variety of reacting conditions were demonstrated. The effect of inlet fuel-air mixture settings, fuel type and bluff body geometry on wake development, flame shape, anchoring and structure, temperatures and combustion efficiencies, over lean and close to blow-off conditions, was presented and analyzed. For the obtained measurements infrared radiation, particle image velocimetry, laser doppler velocimetry, chemiluminescence imaging set-ups, together with Fouriertransform infrared spectroscopy, thermocouples and global emission analyzer instrumentation was employed. This helped to delineate a number of factors that affectcold flow fuel-air mixing, flame anchoring topologies, wake structure development and overall burner performance. The presented data will also significantly assist the validation of computational methodologies for combusting flows and the development of turbulence-chemistry interaction models.

Feature Extraction From Time Resolved Reacting Flow Data Sets

2018 ◽  
Author(s):  
H. Ek ◽  
I. Chterev ◽  
N. Rock ◽  
B. Emerson ◽  
J. Seitzman ◽  
...  
Keyword(s):  
Swirling Flow ◽  
Azimuthal Velocity ◽  
Flow Fields ◽  
Swirl Flow ◽  
Reacting Flow ◽  
Data Sets ◽  
Time Resolved ◽  
Recirculating Flow ◽  
Flow Features ◽  
Dynamical Flow

This paper presents measurements of the simultaneous fuel distribution, flame position and flow velocity in a high pressure, liquid fueled combustor. Its objective is to develop methods to process, display and compare large quantities of instantaneous data with computations. However, time-averaged flow fields rarely represent the instantaneous, dynamical flow fields in combustion systems. It is therefore important to develop methods that can algorithmically extract dynamical flow features and be directly compared between measurements and computations. While a number of data-driven approaches have been previously presented in the literature, the purpose of this paper is to propose several approaches that are based on understanding of key physical features of the flow — for this reacting swirl flow, these include the annular jet, the swirling flow which may be precessing, the recirculating flow between the annular jets, and the helical flow structures in the shear layers. This paper demonstrates nonlinear averaging of axial and azimuthal velocity profiles, which provide insights into the structure of the recirculation zone and degree of flow precession. It also presents probability fields for the location of vortex cores that enables a convenient method for comparison of their trajectory and phasing with computations. Taken together, these methods illustrate the structure and relative locations of the annular fluid jet, recirculating flow zone, spray location, flame location, and trajectory of the helical vortices.

scholarly journals Experimental research in mechanic's field of control for further innovation in the hydraulic and electronic operated injection system

2019 ◽  
Vol 85 ◽  
pp. 08006 ◽  
Author(s):  
Iosif Ferenţi ◽  
Dan Opruţa ◽  
Doru Băldean
Keyword(s):  
Fuel Injection ◽  
Control Unit ◽  
Injection System ◽  
Minimal Amount ◽  
Operational Parameters ◽  
Complete Combustion ◽  
Sport Competition ◽  
Fuel Jet ◽  
Air Intake ◽  
Intake Pressure

In the present research paper is detailed an experimental work concerning Engine Control Unit (ECU) in order to trace predictive trend-lines regarding operational parameters such as ignition timing, fuel supply, injection duty, at more than ten engine speed regimes in the case of a powertrain for motor-sport competition, with distinct air pressures, injector status and spark advances. An experimental study of real values and trend-lines as well as actuator's output data was realized in order to point out electronic control unit's functional characteristics and to redefine the economic field with optimal combustion pressure, efficient mixture formation/burning and diminished emissions as a consequence of the proper measures. Air intake pressure influences the fundamental conditions for intake charge definition and for lambda level even prior to engine cycle beginning in the powertrain with port fuel injection (PFI). Lambda value expresses the operational quality in relation with the excess air intake compared to the minimal amount necessary for a complete combustion of fuel jet charge.

Effects of droplet diameter on instantaneous burning rate of isolated fuel droplets in argon-rich or carbon dioxide-rich ambiences under microgravity

2013 ◽  
Vol 34 (1) ◽  
pp. 1601-1608 ◽  
Author(s):  
Shinji Nakaya ◽  
Kotaro Fujishima ◽  
Mitsuhiro Tsue ◽  
Michikata Kono ◽  
Daisuke Segawa
Keyword(s):  
Carbon Dioxide ◽  
Burning Rate ◽  
Droplet Diameter ◽  
Fuel Droplets

A Computational Model for the Study of Gas Turbine Combustor Dynamics

1999 ◽  
Vol 121 (2) ◽  
pp. 243-248 ◽  
Author(s):  
D. M. Costura ◽  
P. B. Lawless ◽  
S. H. Fankel
Keyword(s):  
Gas Turbine ◽  
Mass Conservation ◽  
Single Step ◽  
Combustion Model ◽  
Reacting Flow ◽  
Gas Turbine Combustor ◽  
Splitting Algorithm ◽  
Simulation Code ◽  
One Dimensional ◽  
Engine Simulation

A dynamic combustor model is developed for inclusion into a one-dimensional full gas turbine engine simulation code. A flux-difference splitting algorithm is used to numerically integrate the quasi-one-dimensional Euler equations, supplemented with species mass conservation equations. The combustion model involves a single-step, global finite-rate chemistry scheme with a temperature-dependent activation energy. Source terms are used to account for mass bleed and mass injection, with additional capabilities to handle momentum and energy sources and sinks. Numerical results for cold and reacting flow for a can-type gas turbine combustor are presented. Comparisons with experimental data from this combustor are also made.

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