scholarly journals Numerical Simulation of Fluid Flow and Combustion in Gas Turbine Combustors

1993 ◽  
Author(s):  
Inge R. Gran ◽  
M. C. Melaaen ◽  
F. Magnussen
Keyword(s):  
Gas Turbine ◽  
Complex Geometry ◽  
Reacting Flows ◽  
Staggered Grid ◽  
Computational Grids ◽  
Turbulent Reacting Flows ◽  
Combustion Chambers ◽  
Gas Turbine Combustors ◽  
Elliptic Differential Equations ◽  
Finite Volume Approach

The finite-volume approach together with body-fitted curvilinear non-orthogonal coordinates and a non-staggered grid arrangement is used for investigating turbulent reacting flows inside gas turbine combustion chambers. The computational grids are generated by solving elliptic differential equations, permitting an accurate description of the complex geometry of commercial gas turbine combustors. Different combustion models are briefly discussed with a view to their suitability for practical combustor predictions. The k-ε model and the Eddy Dissipation Concept are selected to account for the turbulent combustion in the present study. The governing equations and coordinate transformations needed to derive the discretized equations are reviewed. One isothermal and two combusting flow fields are calculated. The calculations are in reasonable agreement with measurements, but the results should be improved by grid refinement and by using a better turbulence model.

An Aid to Learn Computational Fluid Dynamics: Immersed-Boundary-Based Simulation of 2D Flow

Volume 1 ◽  
2004 ◽  
Author(s):  
Sungsu Lee ◽  
Kyung-Soo Yang ◽  
Jong-Yeon Hwang
Keyword(s):  
Complex Geometry ◽  
Mass Conservation ◽  
Computational Method ◽  
Staggered Grid ◽  
Navier Stokes ◽  
Immersed Boundary ◽  
Step Method ◽  
Fractional Step Method ◽  
Navier Stokes Equation ◽  
Finite Volume Approach

Development of geometry-independent computational method and educational codes for simulation of 2D flows around objects of complex geometry is presented. Referred as immersed boundary method, it introduces virtual forcing to governing equations to represent the effect of physical boundaries. The present method is based on a finite-volume approach on a staggered grid with a fractional-step method to solve Navier-Stokes equation and continuity equation. Both momentum and mass forcings are introduced on and inside the object to satisfy no-slip condition and mass conservation. Since Cartesian grid lines in general do not coincide with the immersed boundaries, several interpolation schemes are employed. Several examples are simulated using the method presented in this study and the results agree well with other results. Both user-friendly preprocessor with GUI and FORTRAN-based solver are open to the public for educational purposes.

scholarly journals Notes on the Occurrence and Determination of Carbon Within Gas Turbine Combustors

1988 ◽  
Author(s):  
J. Odgers ◽  
E. R. Magnan
Keyword(s):  
Gas Turbine ◽  
Hydrogen Content ◽  
Carbon Distribution ◽  
Combustion Chambers ◽  
Comprehensive Investigation ◽  
Gas Turbine Combustors ◽  
Series Of Experiments ◽  
Gas Turbine Combustion ◽  
Carbon Determination

Details are presented of two series of experiments to investigate carbon determination in gas turbine combustion chambers. The first series employed a gravimetric technique to examine carbon distribution within the various zones of a combustor with the aim of identifying zones of formation and oxidation. In the second series a fairly comprehensive investigation of the technique of measuring Smoke Number was made with the objective of obtaining details relevant to its accuracy and applicability. Mixtures of iso-octane and benzene were used as fuel, thereby permitting the effects of hydrogen content to be established. The results are correlated with othersome obtained previously.

scholarly journals A Three-Dimensional Algebraic Grid Generation Scheme for Gas Turbine Combustors With Inclined Slots

1992 ◽  
Author(s):  
S. L. Yang ◽  
M. C. Cline ◽  
R. Chen ◽  
Y.-L. Chang
Keyword(s):  
Gas Turbine ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Interpolation Method ◽  
Cross Flow ◽  
Grid Generation ◽  
Temperature Fields ◽  
Computational Grids ◽  
Gas Turbine Combustors ◽  
Ring Shape

Abstract A 3D algebraic grid generation scheme is presented for generating the grid points inside gas turbine combustors with inclined slots. The scheme is based on the 2D transfinite interpolation method. Since the scheme is a 2D approach, it is very efficient and can be easily extended to gas turbine combustors with either dilution hole or slot configurations. To demonstrate the feasibility and the usefulness of the technique, a numerical study of the quick-quench/lean-combustion (QQ/LC) zones of a staged turbine combustor is given. Preliminary results illustrate some of the major features of the flow and temperature fields in the QQ/LC zones. Formation of co- and counter-rotating bulk flow and sandwiched-ring-shape temperature fields, typical of the confined slanted jet-in-cross flow, can be observed clearly. Numerical solutions show the method to be an efficient and reliable tool for generating computational grids for analyzing gas turbine combustors with slanted slots.

Application of CFD-Based Analysis Technique for Design and Optimization of Gas Turbine Combustors

2004 ◽  
Author(s):  
I. G. Koutsenko ◽  
S. F. Onegin ◽  
A. M. Sipatov
Keyword(s):  
Nitric Oxide ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Combustion Products ◽  
Combustion Chambers ◽  
Design And Optimization ◽  
Gas Turbine Combustors ◽  
Analysis Technique ◽  
Nitric Oxide Emissions ◽  
Operational Development

The design and operational development of gas turbine combustors is a complex process, involving a great volume of design and experimental work. The application of computational fluid dynamics (CFD) methods allows to lower the volume of experimental works on operational development of combustors and to make changes to the design of combustion chambers on early design stages. In this paper the application of commercial CFD package CFX-TASCflow for calculation of flow structure and analysis of nitric oxide formation process in the combustion chamber of the PS-90A gas turbine and its modifications is considered. The results of the analysis show, that the basic determinative criterion of a nitric oxide emission level is the residence time of a combustion products in high-temperature zones. With help of this criterion, an optimization of the PS-90A combustion chamber was performed. A design of an optimized combustion chamber allows to achieve a low level of nitric oxide emissions.

Control of Turbulent Combustion Flow Inside a Gas Turbine Combustion Chamber Using Plasma Actuators

2015 ◽  
Author(s):  
E. Ghasemi ◽  
Soheil Soleimanikutanaei ◽  
Cheng-Xian Lin
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Dielectric Material ◽  
Computational Simulation ◽  
Reacting Flows ◽  
Navier Stokes ◽  
Turbulent Reacting Flows ◽  
Chemical Reaction Kinetics ◽  
Copper Electrodes ◽  
Gas Turbine Combustion

In this paper, effects of a standard plasma actuator on non-premixed turbulent reacting flows in a unique gas turbine combustion chamber have been studied numerically. The computational simulation is conducted by employing the Reynolds Averaged Navier-Stokes (RANS) approach. Chemical reaction kinetics has been modeled using the eddy dissipation concept (EDC) model. The numerical simulation has been carried out by Finite Element Methods. High voltage potential between two copper electrodes separated by a dielectric material has been applied which leads to the generation of plasma and an electric field, which creates a body force. It was found that by orienting the plasma force in the desired direction, combustion rate can be accelerated or controlled. The numerical results have been presented through velocity, temperature, and species concentration profiles under different combustion conditions.

On Meshing Guidelines for Large Eddy Simulations of Gas Turbine Combustors

2014 ◽  
Author(s):  
Krishna Kant Agarwal ◽  
Srinivasa Rao Konakalla ◽  
Senthamil Selvan
Keyword(s):  
Gas Turbine ◽  
Complex Geometry ◽  
Mesh Size ◽  
Large Eddy Simulations ◽  
Mean Flow ◽  
Length Scales ◽  
Combustion Dynamics ◽  
Gas Turbine Combustors ◽  
Large Eddy ◽  
Filter Size

Large Eddy Simulations (LES) is increasingly becoming a feasible tool for industrial design purposes on account of ongoing advancements in computational power. It is a promising arena in the field of computational fluid dynamics where more details of flow-turbulence are explicitly captured and lesser are modeled as compared to the traditional Reynolds-average (RANS) approaches. For the gas turbine combustors particularly, it is a promising tool for better predictions of reactants mixing and hence the combustion, flame shape and temperature profiles. Also, as inherent unsteady nature of the flow is captured, it can predict combustion dynamics due to heat-release (and hence pressure) fluctuations. The main factor for performing a successful and reliable LES is to find an appropriate filter size for different regions of the CFD domain. This filter size is typically same as the CFD mesh size and turbulent scales larger than this are explicitly solved in LES. In industrial gas turbine combustors, due to complex geometry and numerous small cooling flow passages, unnecessary mesh refinement may make the mesh size prohibitive for a time-marching LES simulation. Hence, judicious selection of important flow features and geometry is important. Still not much experience is available on the quantification of LES meshing requirements for practical gas turbine combustors. In this study, two different LES meshing approaches, namely one based on Taylor length scales and other based on theoretical turbulence energy spectrum are compared for various medium scale gas turbine combustors. While the former approach requires a prior RANS simulation and provides a spatial distribution of the grid size, the latter just requires mean flow properties and global length scale at various inlets but produces only a global mesh value. It is found for all combustor designs under study that the two approaches agree well with each other for predicting mesh size requirements for LES where 85–90% of turbulent length scales are captured. This helps towards standardizing LES meshing procedure in industrial scenarios and helps a user to choose meshing option based on the level of details needed and time-resource constraints.

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