scholarly journals Numerical Correlation of Gas Turbine Combustor Ignition

1988 ◽  
Author(s):  
F. P. Lee ◽  
T. Koblish ◽  
N. Marchionna
Keyword(s):  
Gas Turbine ◽  
Flow Conditions ◽  
Gas Turbine Combustor ◽  
Ignition Probability ◽  
Ignition Point ◽  
Fuel Injectors ◽  
Fuel Droplets ◽  
Ignition Characteristics ◽  
Droplet Tracking ◽  
Starting Flow

In single can combustor ignition tests, different results were obtained for pressure atomizing and airblast atomizing fuel injectors as well as for various ignition locations. In order to understand the effect of fuel spray characteristics and ignition locations on gas turbine combustion ignition characteristics, a computer simulation of fuel droplet ignition at engine starting flow conditions has been conducted. An ignition model for evaporating fuel droplets was incorporated with the numerical droplet tracking scheme in the computational flow field, which included a simulated ignition point source. A large number of various size droplets were computed for their trajectories and ignition reactions. A statistical data base was established to calculate the ignition probability of droplets in terms of number and mass fraction. A correlation between predicted ignition probability trends and experimental ignition data for two different injector/ignitor configurations was demonstrated.

Experimental Investigation of the Flow Inside a Water Model of a Gas Turbine Combustor: Part 1—Mean and Turbulent Flowfield

1995 ◽  
Vol 117 (3) ◽  
pp. 450-458 ◽  
Author(s):  
J. J. McGuirk ◽  
J. M. L. M. Palma
Keyword(s):  
Experimental Data ◽  
Gas Turbine ◽  
Laser Doppler Velocimetry ◽  
Recirculation Zone ◽  
Water Model ◽  
Doppler Velocimetry ◽  
Flow Conditions ◽  
Gas Turbine Combustor ◽  
High Turbulence ◽  
The Mean

The present study examines the flow inside the water model of a gas turbine combustor, with the two main objectives of increasing the understanding of this type of flow and providing experimental data to assist the development of mathematical models. The main features of the geometry are the interaction between two rows of radially opposed jets penetrating a cross-flowing axial stream with and without swirl, providing a set of data of relevance to all flows containing these features. The results, obtained by laser Doppler velocimetry, showed that under the present flow conditions, the first row of jets penetrate almost radially into the combustor and split after impingement, giving rise to a region of high turbulence intensity and a toroidal recirculation zone in the head of the combustor. Part 1 discusses the mean and turbulent flowfield, and the detailed study of the region near the impingement of the first row of jets is presented in Part 2 of this paper.

Effect of Downstream Contraction on Liner Heat Transfer in a Gas Turbine Combustor Swirl Flow

2015 ◽  
Author(s):  
Sandeep Kedukodi ◽  
Srinath Ekkad
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Swirl Flow ◽  
Reacting Flow ◽  
Flow Profile ◽  
Flow Conditions ◽  
Gas Turbine Combustor ◽  
Inlet Flow ◽  
Flow Simulations ◽  
Accelerated Flow

Established numerical approaches for performing detailed flow analysis happens to be an effective tool for industry based applied research. In the present study, computations are performed on multiple gas turbine combustor geometries for turbulent, non-reactive and reactive swirling flow conditions for an industrial swirler. The purpose of this study is to identify the location of peak convective heat transfer along the combustor liner under swirling inlet flow conditions and to investigate the influence of combustor geometry on the flow field. Instead of modeling the actual swirler along with the combustor, an inlet swirl flow profile is applied at the inlet boundary based on previous literature. Initially, the computed results are validated against available experimental data for an inlet Reynolds number flow of 50000 using a 2D axi-symmetric flow domain for non-reacting conditions. A constant heat flux on the liner is applied for the study. Two turbulence models (RNG k-ε and k-ω SST) are utilized for the analysis based on its capability to simulate swirling flows. It is found that both models predict the peak liner heat transfer location similar to experiments. However, k-ε RNG model predicts heat transfer magnitude much closer to the experimental values except displaying an additional peak whereas k-ω model predicts only one peak but tends to over-predict in magnitude. Since the overall characteristic liner heat transfer trend is captured well by the latter one, it is chosen for future computations. A 3D sector (30°) model results also show similar trends as 2D studies. Simulations are then extended to 3 different combustors (Case 1: full cylinder and Case 2 and 3: cylinders with downstream contractions having reduced exit areas) by adopting the same methodology for same inlet flow conditions. Non-reacting simulations predict that the peak heat transfer location is marginally reduced by the downstream contraction of the combustor. However the peak location shifts towards downstream due to the presence of accelerated flow. Reacting flow simulations are performed with Flamelet Generation Manifold (FGM) model for simulating premixed combustion for the same inlet flow conditions as above. It is observed that Case 3 predicts a threefold increase in the exit flow velocity in comparison to non-reacting flow simulations. The liner heat transfer predictions show that both geometries predict similar peak temperatures. However, only one fourth of the initial liner length experiences peak temperature for Case 1 whereas the latter continues to feel the peak till the end. This behavior of Case 3 can be attributed to rapid convection of high temperature products downstream due to the prevailing accelerated flow.

scholarly journals Flow conditions analysis of Gas Turbine Combustor

2020 ◽  
Vol 995 ◽  
pp. 012043
Author(s):  
R Abinaya ◽  
D Rohini ◽  
B Soundarya ◽  
S Balakrishnan ◽  
B Dakshinamurthy ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Flow Conditions ◽  
Gas Turbine Combustor

Flow characteristics in the liner of a reverse-flow gas turbine combustor

2001 ◽  
Vol 215 (4) ◽  
pp. 443-451 ◽  
Author(s):  
S Bharani ◽  
S. N. Singh ◽  
D. P. Agrawal
Keyword(s):  
Gas Turbine ◽  
Turbulence Intensity ◽  
Reverse Flow ◽  
Flow Characteristics ◽  
Flow Distribution ◽  
Isothermal Flow ◽  
Flow Conditions ◽  
Gas Turbine Combustor ◽  
Plane Model ◽  
Uniform Flow Distribution

Investigation carried out in a plane model of a reverse-flow gas turbine combustor under isothermal flow conditions has shown that the bulk of the flow remains close to the outer liner wall between the rows of primary and dilution holes, while it shifts towards the liner mid-plane after the row of dilution holes. At the combustor outlet, the bulk of the flow remains towards the inner wall of the outlet duct, with a uniform flow distribution. At the outlet of the combustor model, turbulence intensity was approximately three times higher than that at the inlet plane.

Measurements of Equivalence Ratio Fluctuations in a Lean Premixed Gas Turbine Combustor Using an IR Absorption Technique

2010 ◽  
Author(s):  
Hyung Ju Lee ◽  
Kyu Tae Kim ◽  
Jong Guen Lee ◽  
Bryan D. Quay ◽  
Domenic A. Santavicca
Keyword(s):  
Gas Turbine ◽  
Equivalence Ratio ◽  
Fuel Injection ◽  
Time Lag ◽  
Ir Absorption ◽  
Time Lags ◽  
Gas Turbine Combustor ◽  
Fuel Injectors ◽  
Lean Premixed ◽  
Absorption Technique

An experimental study was conducted to estimate and confirm equivalence ratio fluctuations at the inlet of a lean premixed gas turbine combustor. Fuel injectors were placed at several locations in the mixing section of the combustor, in order to produce different instability characteristics due to the equivalence ratio fluctuations. An IR absorption technique was used to measure the equivalence ratio fluctuations at the inlet of the dump combustor. The measured IR signals were processed in two different ways and the results were compared to confirm the two calibrated equivalence ratio signals. The processed data showed that the two processing methods gave very similar results, and the phase of the measured equivalence ratio fluctuations at the combustor inlet by the IR absorption technique agreed well with that of equivalence ratio fluctuations predicted by time lags in the mixing section. It was, however, not possible to accurately predict the magnitude of the equivalence ratio fluctuations at the combustor inlet by the time lag analysis because the equivalence ratio fluctuations generataed at the fuel injection location is changed by mixing and diffusion as the fuel is convected through the combustor.

Investigation of Ignition Probability in a Gas Turbine Combustor Using Laser Ignition

1999 ◽  
Author(s):  
R. A. Hicks ◽  
C. W. Wilson ◽  
C. G. W. Sheppard ◽  
R. Woolley ◽  
J. Wyatt
Keyword(s):  
Gas Turbine ◽  
Probability Model ◽  
Surface Discharge ◽  
Laser Ignition ◽  
Gas Turbine Combustor ◽  
Ignition Probability ◽  
Turbine Engine ◽  
Flame Kernel ◽  
Inlet Conditions ◽  
Comparative Results

For an aircraft gas turbine engine, the ignition performance is usually expressed in terms of the range of flight conditions over which stable combustion can be established. At present, the size of an aircraft’s gas turbine combustor is governed predominately by its altitude relight performance and is principally derived from existing empirical design rules. These indicate the volume required to give adequate primary zone airodynamic loading to achieve the desired relight performance. A possible means of improving altitude relight performance is to relocate the point of ignition away from the combustor wall to a more favourable location within the combustion chamber. One way of achieving this is through the use of laser ignition. Reported in the paper is an initial programme of work in which the possibility of using laser ignition has been investigated in a gas turbine research combustor operating at several inlet conditions. Comparative results show that, when sited at the same location, laser ignition gave no noticeable improvement in ignition performance when compared to a standard surface discharge igniter (SDI). However, by using laser ignition to locate the ignition site away from the combustor wall, the range of combustor mass flow and AFR at which ≥75% ignition probability could be achieved was increased by approximately 33%. In conjunction with the experimental study, an ignition probability model, based on the local magnitude of a Karlovitz stretch factor, has been developed to identify suitable regions within the combustor in which to apply laser ignition. The Karlovitz parameter gives an indication as to whether or not a flame kernel will propagate successfully and has been used in conjunction with flow field and scalar distributions generated by Computational Fluid Dynamics (CFD) to yield a 2D map of ignition probability. However, the sensitivity shown by the model to the accuracy of the CFD predictions meant that reliable estimates of optimum ignition sites could only be obtained using experimental fuel and turbulence intensity distributions.

A Numerical Study of Spray Injected in a Gas Turbine Lean Pre-Mixed Pre-Vaporized Combustor

2015 ◽  
Vol 32 (1) ◽  
Author(s):  
Amedeo Amoresano ◽  
Maria Cristina Cameretti ◽  
Raffaele Tuccillo
Keyword(s):  
Experimental Data ◽  
Gas Turbine ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Spray Parameters ◽  
Flow Conditions ◽  
Gas Turbine Combustor ◽  
Flow Solver ◽  
Combustion Simulation ◽  
Fuel Vapour

AbstractThe authors have performed a numerical study to investigate the spray evolution in a modern gas turbine combustor of the Lean Pre-Mixed Pre-vaporized type. The CFD tool is able to simulate the injection conditions, by isolating and studying some specific phenomena. The calculations have been performed by using a 3-D fluid dynamic code, the FLUENT flow solver, by choosing the injection models on the basis of a comparative analysis with some experimental data, in terms of droplet diameters, obtained by PDA technique.In a first phase of the investigation, the numerical simulation refers to non-evaporating flow conditions, in order to validate the estimation of the fundamental spray parameters. Next, the calculations employ boundary conditions close to those occurring in the actual combustor operation, in order to predict the fuel vapour distribution throughout the premixing chamber. The results obtained allow the authors to perform combustion simulation in the whole domain.

Flow Field and Wall Temperature Measurements for Reacting Flow in a Lean Premixed Swirl Stabilized Can Combustor

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Suhyeon Park ◽  
David Gomez-Ramirez ◽  
Siddhartha Gadiraju ◽  
Sandeep Kedukodi ◽  
Srinath V. Ekkad ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Gas Turbine ◽  
Swirling Flow ◽  
Single Case ◽  
Operating Conditions ◽  
Reacting Flow ◽  
Flow Conditions ◽  
Gas Turbine Combustor ◽  
Lean Premixed

In this study, we provide detailed wall heat flux measurements and flow details for reacting flow conditions in a model combustor. Heat transfer measurements inside a gas turbine combustor provide one of the most serious challenges for gas turbine researchers. Gas turbine combustor improvements require accurate measurement and prediction of reacting flows. Flow and heat transfer measurements inside combustors under reacting flow conditions remain a challenge. The mechanisms of thermal energy transfer must be investigated by studying the flow characteristics and associated heat load. This paper experimentally investigates the effects of combustor operating conditions on the reacting flow in an optical single can combustor. The swirling flow was generated by an industrial lean premixed, axial swirl fuel nozzle. Planar particle image velocimetry (PIV) data were analyzed to understand the characteristics of the flow field. Liner surface temperatures were measured in reacting condition with an infrared camera for a single case. Experiments were conducted at Reynolds numbers ranging between 50,000 and 110,000 (with respect to the nozzle diameter, DN); equivalence ratios between 0.55 and 0.78; and pilot fuel split ratios of 0 to 6%. Characterizing the impingement location on the liner, and the turbulent kinetic energy (TKE) distribution were a fundamental part of the investigation. Self-similar characteristics were observed at different reacting conditions. Swirling exit flow from the nozzle was found to be unaffected by the operating conditions with little effect on the liner. Comparison between reacting and nonreacting flows (NR) yielded very interesting and striking differences.

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