Numerical Simulation of Non-Reacting and Reacting Flows in a 5MW Commercial Gas Turbine Combustor

2009 ◽  
Author(s):  
Daero Jeong ◽  
Kang Y. Huh
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Measurement Data ◽  
Turbulence Models ◽  
Swirl Flow ◽  
Reacting Flows ◽  
Reacting Flow ◽  
Mean Flow ◽  
Gas Turbine Combustor ◽  
Swirl Flame

This study is concerned with numerical simulation of a simple swirl flame and a 5MW commercial gas turbine combustor both operating on methane/air. Validation is performed for turbulent flow and combustion models against some measurement data (http://public.ca.sandia.gov/TNF/swirlflames.html). Evaluation is performed for the standard k-e and the realizable k-e models in the nonreacting swirl flow and the EBU (eddy breakup) and the PPDF (presumed probability density function) models in the reacting flow of the 5 MW commercial 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. Important geometrical details such as air swirlers, vane passages and liner holes are taken into account. Different turbulence models result in similar flow patterns with varying sizes of the recirculation pockets in the central region and at the outside corner. The EBU and the PPDF models show similar downstream distributions of mean flow and temperature, while the EBU shows a lifted flame with a stronger effect of swirl due to limited increase of axial momentum by volume expansion near the nozzle.

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.

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.

Large-Eddy Simulation of Reacting Turbulent Flows in Complex Geometries

2005 ◽  
Vol 73 (3) ◽  
pp. 374-381 ◽  
Author(s):  
K. Mahesh ◽  
G. Constantinescu ◽  
S. Apte ◽  
G. Iaccarino ◽  
F. Ham ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Turbulent Flows ◽  
Reacting Flows ◽  
Gas Turbine Combustor ◽  
Turbine Engine ◽  
Progress Variable ◽  
Eddy Simulation ◽  
Variable Approach ◽  
Large Eddy

Large-eddy simulation (LES) has traditionally been restricted to fairly simple geometries. This paper discusses LES of reacting flows in geometries as complex as commercial gas turbine engine combustors. The incompressible algorithm developed by Mahesh et al. (J. Comput. Phys., 2004, 197, 215–240) is extended to the zero Mach number equations with heat release. Chemical reactions are modeled using the flamelet/progress variable approach of Pierce and Moin (J. Fluid Mech., 2004, 504, 73–97). The simulations are validated against experiment for methane-air combustion in a coaxial geometry, and jet-A surrogate/air combustion in a gas-turbine combustor geometry.

Three-Dimensional Computation of Gas Turbine Combustors and the Validation Studies of Turbulence and Combustion Models

1997 ◽  
Author(s):  
D. Biswas ◽  
K. Kawano ◽  
H. Iwasaki ◽  
M. Ishizuka ◽  
S. Yamanaka
Keyword(s):  
Gas Turbine ◽  
Validation Studies ◽  
Three Dimensional ◽  
Chemical Species ◽  
Reaction Rates ◽  
Reacting Flows ◽  
Gas Turbine Combustor ◽  
Combustion Models ◽  
Rate Of Dissipation

The main aim or the present work is to explore computational fluid dynamics and related turbulence and combustion models for application to the design, understanding and development of gas turbine combustor. Validation studies were conducted using the Semi-Implicit Method for Pressure Linked Equations (SIMPLE) scheme to solve the relevant steady, elliptical partial differential equations of the conservation of mass, momentum, energy and chemical species in three-dimensional cylindrical co-ordinate system to simulate the gas turbine combustion chamber configurations. A modified version of k-ε turbulence model was used for characterization of local turbulence in gas turbine combustor. Since, in the present study both diffusion and pre-mixed combustion were considered, in addition to familiar bi-molecular Arhenius relation, influence of turbulence on reaction rates was accounted for based on the eddy break up concept of Spalding and was assumed that the local reaction rate was proportional to the rate of dissipation of turbulent eddies. Firstly, the validity of the present approach with the turbulence and reaction models considered is checked by comparing the computed results with the standard experimental data on recirculation zone, mean axial velocity and temperature profiles, etc. for confined, reacting and non-reacting flows with reasonably well defined boundary conditions. Finally, the results of computation for practical gas turbine combustor using combined diffusion and pre-mixed combustion for different combustion conditions are discussed.

Numerical Simulation for Free Turbulent Reacting Flow by Particle Method

2003 ◽  
Author(s):  
Tomomi Uchiyama ◽  
Naohiro Otsuki
Keyword(s):  
Numerical Simulation ◽  
Chemical Reaction ◽  
Mixing Layer ◽  
Particle Method ◽  
Reacting Flows ◽  
Single Step ◽  
Reacting Flow ◽  
Turbulent Reacting Flows ◽  
Plane Mixing Layer ◽  
Irreversible Chemical Reaction

This paper presents a particle method for free turbulent reacting flows. The vorticity and concentration fields are discretized into the vortex and concentration elements, respectively, and the behavior of the elements is calculated with the Lagrangian method. The chemical reaction is estimated through the Lagrangian calculation for the strength of concentration element. The particle method is applied to simulate a plane mixing layer with a single-step and irreversible chemical reaction of non-premixed reactants so as to discuss the applicability.

CFD Analysis of Industrial Gas Turbine Exhaust Diffusers

2002 ◽  
Author(s):  
V. Vassiliev ◽  
S. Irmisch ◽  
S. Florjancic
Keyword(s):  
Gas Turbine ◽  
Measurement Data ◽  
Turbulence Models ◽  
Cfd Analysis ◽  
Cfd Modelling ◽  
Gas Turbine Exhaust ◽  
Key Aspects ◽  
Industrial Gas Turbine ◽  
Turbine Exhaust

The key aspects for the reliable CFD modelling of exhaust diffusers are addressed in this paper. In order to identify adequate turbulence models a number of 2D diffuser configurations have been simulated using different turbulence models and results have been compared with measurements. An automated procedure for a time- and resource-efficient and accurate prediction of complex diffuser configuration is presented. The adequate definitions of boundary conditions for the diffuser simulation using this procedure are discussed. In the second part of this paper, the CFD procedure is being applied to investigate the role of secondary flow on axial diffusers. Prediction results are discussed and compared with available measurement data.

Combustion Instability in a Swirl Flow Combustor With Transverse Extensions

2013 ◽  
Author(s):  
Aditya Saurabh ◽  
C. O. Paschereit
Keyword(s):  
Flow Field ◽  
Combustion Instability ◽  
Swirl Flow ◽  
Reacting Flows ◽  
Acoustic Oscillations ◽  
Test Rig ◽  
Thermoacoustic Instability ◽  
Transverse Acoustic ◽  
Axisymmetric Shear ◽  
Swirl Flame

The present investigation is an analysis of self-excited combustion instability in a swirl flame-based combustor with transverse extensions. Transverse extensions create the possibility of studying flame interaction with transverse acoustic oscillations. Such investigation important for understanding the phenomenon of thermoacoustic instability in annular combustors, where during thermoacoustic instability, azimuthal acoustic modes of the combustor couple with the multiple flames of the combustor. Flame and flow field dynamics during self-excited thermoacoustic instability in the single burner test-rig is presented here. These results are then compared to the dynamics of the isothermal and reacting flows in response to axial and transverse acoustic forcing. Both axial and transverse forcing led to the formation of axisymmetric shear layer vortices. Adding to the insight gained from previous investigations, these results suggest that that swirl flow dynamics in response to transverse acoustics consists of a non-trivial, direct effect of transverse acoustics on the flow field, in addition to its response to longitudinal fluctuations induced by transverse forcing.

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