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.

A Computational Model for the Study of Gas Turbine Combustor Dynamics

1998 ◽  
Author(s):  
David M. Costura ◽  
Patrick B. Lawless ◽  
Steven H. Frankel
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.

scholarly journals Scale-Resolving Simulation of a Propane-Fuelled Industrial Gas Turbine Combustor Using Finite-Rate Tabulated Chemistry

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 126 ◽  
Author(s):  
Kai Zhang ◽  
Ali Ghobadian ◽  
Jamshid M. Nouri
Keyword(s):  
Gas Turbine ◽  
Chemical Reaction ◽  
Turbulent Flame ◽  
Lower Amount ◽  
Combustion Model ◽  
Gas Turbine Combustor ◽  
Finite Rate ◽  
Chemistry Method ◽  
Tabulated Chemistry ◽  
Partially Premixed

The scale-resolving simulation of a practical gas turbine combustor is performed using a partially premixed finite-rate chemistry combustion model. The combustion model assumes finite-rate chemistry by limiting the chemical reaction rate with flame speed. A comparison of the numerical results with the experimental temperature and species mole fraction clearly showed the superiority of the shear stress transport, K-omega, scale adaptive turbulence model (SSTKWSAS). The model outperforms large eddy simulation (LES) in the primary region of the combustor, probably for two reasons. First, the lower amount of mesh employed in the simulation for the industrial-size combustor does not fit the LES’s explicit mesh size dependency requirement, while it is sufficient for the SSTKWSAS simulation. Second, coupling the finite-rate chemistry method with the SSTKWSAS model provides a more reasonable rate of chemical reaction than that predicted by the fast chemistry method used in LES simulation. Other than comparing with the LES data available in the literature, the SSTKWSAS-predicted result is also compared comprehensively with that obtained from the model based on the unsteady Reynolds-averaged Navier–Stokes (URANS) simulation approach. The superiority of the SSTKWSAS model in resolving large eddies is highlighted. Overall, the present study emphasizes the effectiveness and efficiency of coupling a partially premixed combustion model with a scale-resolving simulation method in predicting a swirl-stabilized, multi-jets turbulent flame in a practical, complex gas turbine combustor configuration.

Numerical Characterisation of a Gas Turbine Model Combustor Applying Scale-Adaptive Simulation

2009 ◽  
Author(s):  
Axel Widenhorn ◽  
Berthold Noll ◽  
Manfred Aigner
Keyword(s):  
Flow Field ◽  
Gas Turbine ◽  
Mixture Fraction ◽  
Thermal Power ◽  
Three Dimensional ◽  
Combustion Model ◽  
Reacting Flow ◽  
Adaptive Simulation ◽  
Power Load ◽  
Turbine Model

In this contribution the three-dimensional reacting turbulent flow field of a swirl-stabilized gas turbine model combustor is analyzed numerically. The investigated partially premixed and lifted CH4/air flame has a thermal power load of Pth = 35kW and a global equivalence ratio of φ = 0.65. To study the reacting flow field the Scale Adaptive Simulation (SAS) turbulence model in combination with the Eddy Dissipation/Finite Rate Chemistry combustion model was applied. The simulations were performed using the commercial CFD software package ANSYS CFX-11.0. The numerically achieved time-averaged values of the velocity components and their appropriate turbulent fluctuations (RMS) are in very good agreement with the experimental values (LDA). The same excellent results were found for other flow quantities like temperature and mixture fraction. Here, the corresponding time-averaged and the appropriate RMS profiles are compared to Raman measurements. Furthermore the instantaneous flow features are discussed. In accordance with the experiment the numerical simulation evidences the existence of a precessing vortex core (PVC). The PVC rotates with a frequency of 1596Hz. Moreover it is shown that in the upper part of the combustion chamber a tornado-like vortical structure is established.

Study of Flame Stability in a Step Swirl Combustor

1996 ◽  
Vol 118 (2) ◽  
pp. 308-315 ◽  
Author(s):  
M. D. Durbin ◽  
M. D. Vangsness ◽  
D. R. Ballal ◽  
V. R. Katta
Keyword(s):  
Gas Turbine ◽  
Recirculation Zone ◽  
Swirling Flow ◽  
Tangential Velocity ◽  
Combustion Stability ◽  
Combustion Model ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Swirl Combustor ◽  
Radial Profiles

A prime requirement in the design of a modern gas turbine combustor is good combustion stability, especially near lean blowout (LBO), to ensure an adequate stability margin. For an aeroengine, combustor blow-off limits are encountered during low engine speeds at high altitudes over a range of flight Mach numbers. For an industrial combustor, requirements of ultralow NOx emissions coupled with high combustion efficiency demand operation at or close to LBO. In this investigation, a step swirl combustor (SSC) was designed to reproduce the swirling flow pattern present in the vicinity of the fuel injector located in the primary zone of a gas turbine combustor. Different flame shapes, structure, and location were observed and detailed experimental measurements and numerical computations were performed. It was found that certain combinations of outer and inner swirling air flows produce multiple attached flames, aflame with a single attached structure just above the fuel injection tube, and finally for higher inner swirl velocity, the flame lifts from the fuel tube and is stabilized by the inner recirculation zone. The observed difference in LBO between co- and counterswirl configurations is primarily a function of how the flame stabilizes, i.e., attached versus lifted. A turbulent combustion model correctly predicts the attached flame location(s), development of inner recirculation zone, a dimple-shaped flame structure, the flame lift-off height, and radial profiles of mean temperature, axial velocity, and tangential velocity at different axial locations. Finally, the significance and applications of anchored and lifted flames to combustor stability and LBO in practical gas turbine combustors are discussed.

A model for combustor dynamics for inclusion in a dynamic gas turbine engine simulation code

1997 ◽  
Author(s):  
David Costura ◽  
Tomas Velez ◽  
Patrick Lawless ◽  
Steven Frankel ◽  
David Costura ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Simulation Code ◽  
Turbine Engine ◽  
Engine Simulation

Prediction of CO Emission Index for Aviation Gas Turbine Combustor Using Flamelet Generated Manifold Combustion Model

2021 ◽  
Author(s):  
Saurabh Patwardhan ◽  
Pravin Nakod ◽  
Stefano Orsino ◽  
Rakesh Yadav ◽  
Fang Xu ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Liquid Fuel ◽  
Operating Conditions ◽  
Turbine Engines ◽  
Combustion Model ◽  
Gas Turbine Engines ◽  
Gas Turbine Combustor ◽  
Flamelet Generated Manifold ◽  
Emission Index ◽  
Co Emission

Abstract Carbon monoxide (CO) has been identified as one of the regulated pollutants and gas turbine manufacturers target to reduce the CO emission from their gas turbine engines. CO forms primarily when carbonous fuels are not burnt completely, or products of combustion are quenched before completing the combustion. Numerical simulations are effective tools that allow a better understanding of the mechanisms of CO formation in gas turbine engines and are useful in evaluating the effect of different parameters like swirl, fuel atomization, mixing etc. on the overall CO emission for different engine conditions like idle, cruise, approach and take off. In this paper, a thorough assessment of flamelet generated manifold (FGM) combustion model is carried out to predict the qualitative variation and magnitude of CO emission index with the different configurations of a Honeywell test combustor operating with liquid fuel under idle condition, which is the more critical engine condition for CO emission. The different designs of the test combustor are configured in such a way that they yield different levels of CO and hence are ideal to test the accuracy of the combustion model. Large eddy simulation (LES) method is used for capturing the turbulence accurately along with the FGM combustion model that is computationally economical compared to the detailed/reduced chemistry modeling using finite rate combustion model. Liquid fuel spray breakup is modeled using stochastic secondary droplet (SSD) model. Four different configurations of the aviation gas turbine combustor are studied in this work referring to earlier work by Xu et al. [1]. It is shown that the FGM model can predict CO trends accurately. The other global parameters like exit temperature, NOx emissions, pattern factor also show reasonable agreement with the test data. The sensitivity of the CO prediction to the liquid fuel droplet breakup model parameters is also studied in this work. Although the trend of CO variation is captured for different values of breakup parameters, the absolute magnitude of CO emission index differs significantly with the change in the values of breakup parameters suggesting that the spray has a larger impact on the quantitative prediction of CO emission. An accurate prediction of CO trends at idle conditions using FGM model extends the applicability of FGM model to predict different engine operating conditions for different performance criteria accurately.

3D RANS Simulation of Turbulent Flow and Combustion in a 5 MW Reverse-Flow Type Gas Turbine Combustor

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
Daero Joung ◽  
Kang Y. Huh
Keyword(s):  
Turbulent Flow ◽  
Gas Turbine ◽  
Reverse Flow ◽  
Measurement Data ◽  
Swirl Flow ◽  
Reacting Flow ◽  
Mean Flow ◽  
Gas Turbine Combustor ◽  
Rans Simulation ◽  
Combustion Models

This study is concerned with 3D RANS simulation of turbulent flow and combustion in a 5 MW commercial gas turbine combustor. The combustor under consideration is a reverse flow, dry low NOx type, in which methane and air are partially mixed inside swirl vanes. We evaluated different turbulent combustion models to provide insights into mixing, temperature distribution, and emission in the combustor. Validation is performed for the models in STAR-CCM+ against the measurement data for a simple swirl flame (http://public.ca.sandia.gov/TNF/swirlflames.html). The standard k-ε model with enhanced wall treatment is employed to model turbulent swirl flow, whereas eddy break-up (EBU), presumed probability density function laminar flamelet model, and partially premixed coherent flame model (PCFM) are tried for reacting flow in the combustor. Independent simulations are carried out for the main and pilot nozzles to avoid flashback and to provide realistic inflow boundary conditions for the combustor. Geometrical details such as air swirlers, vane passages, and liner holes are all taken into account. Tested combustion models show similar downstream distributions of the mean flow and temperature, while EBU and PCFM show a lifted flame with stronger effects of swirl due to limited increase in axial momentum by expansion.

CFD Modeling of Non-Premixed Combustion in a Gas Turbine Combustor

2002 ◽  
Author(s):  
Kitano Majidi
Keyword(s):  
Gas Turbine ◽  
Transport Model ◽  
Direct Injection ◽  
Turbulence Models ◽  
Cfd Modeling ◽  
Navier Stokes ◽  
Reacting Flow ◽  
Gas Temperature ◽  
Gas Turbine Combustor ◽  
Reynolds Stress Transport Model

In the present study numerical calculations are used to solve reacting flow in a gas turbine combustor. A 3-D Favre-Averaged Navier-Stokes solver for a mixture of chemically reacting gases is applied to predict the flow pattern, gas temperature and fuel and species concentrations in the entire combustor. The complete combustor geometry with all important details such as air swirler vane passages and secondary holes are modeled. The calculations are carried out using three different turbulence models. Comparisons are made between the standard k-ε model, RNG k-ε model and a Reynolds stress transport model. To provide a closure for the chemical source term the Eddy Dissipation model is used. A lean direct injection of a liquid fuel is employed. Furthermore the influence of radiation will be investigated.

Study of Flame Stability in a Step Swirl Combustor

1995 ◽  
Author(s):  
Mark D. Durbin ◽  
Marlin D. Vangsness ◽  
Dilip R. Ballal ◽  
Viswanath R. Katta
Keyword(s):  
Gas Turbine ◽  
Recirculation Zone ◽  
Swirling Flow ◽  
Tangential Velocity ◽  
Combustion Stability ◽  
Combustion Model ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Swirl Combustor ◽  
Radial Profiles

A prime requirement in the design of a modem gas turbine combustor is good combustion stability, especially near lean blowout (LBO), to ensure an adequate stability margin. For an aeroengine, combustor blow-off limits are encountered during low engine speeds at high altitudes over a range of flight Mach numbers. For an industrial combustor, requirements of ultra-low NOx emissions coupled with high combustion efficiency demand operation at or close to LBO. In this investigation, a step swirl combustor (SSC) was designed to reproduce the swirling flow pattern present in the vicinity of the fuel injector located in the primary zone of a gas turbine combustor. Different flame shapes, structure and location were observed and detailed experimental measurements and numerical computations were performed. It was found that certain combinations of outer and inner swirling air flows produce multiple attached flames, a flame with a single attached structure just above the fuel injection tube, and finally for higher inner swirl velocity, the flame lifts from the fuel tube and is stabilized by the inner recirculation zone. The observed difference in LBO between co- and counter-swirl configurations is primarily a function of how the flame stabilizes i.e., attached vs. lifted. A turbulent combustion model correctly predicts the attached flame location(s), development of inner recirculation zone, a dimple-shaped flame structure, the flame lift-off height, and radial profiles of mean temperature, axial velocity, and tangential velocity at different axial locations. Finally, the significance and applications of anchored and lifted flames to combustor stability and LBO in practical gas turbine combustors are discussed.

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