Gas Turbine Combustor: Modelling and Optimization

2005 ◽  
Author(s):  
V. Ganesan ◽  
V. Jyothish Kumar
Keyword(s):  
Gas Turbine ◽  
Three Dimensional ◽  
Field Analysis ◽  
Gas Turbine Combustor ◽  
Cold Flow ◽  
Flow Losses ◽  
Flow Through ◽  
Flow Field Analysis ◽  
Probability Density Function Pdf ◽  
Modelling And Optimization

Present work is concerned with the flow field analysis inside an annular gas turbine combustor both under non-reacting and reacting conditions. Three-dimensional gas turbine combustor of 20-degree sector has been modeled using the pre-processor GAMBIT. Flow through the combustor has been simulated using FLUENT code by solving the appropriate governing equations viz., conservation of mass, momentum and energy. RNG κ-ε turbulence model is used for physical modeling. Initially prediffuser optimization has been carried out with respect to angle, length and contours. Flow through holes is modeled using porous jump boundary condition as well as modeling real holes themselves to study the efficacy of real hole modeling. Total pressure loss has been calculated to evaluate the cold flow as well as hot flow losses. Combustion has been modeled using the Probability Density Function (PDF) approach. Temperature and species concentrations are predicted.

scholarly journals Modeling of marine gas turbine combustor under non-reacting and reacting conditions

1970 ◽  
Vol 2 (1) ◽  
pp. 21-32 ◽  
Author(s):  
V Jyothishkumar ◽  
V Ganesan
Keyword(s):  
Gas Turbine ◽  
Pressure Loss ◽  
Three Dimensional ◽  
Field Analysis ◽  
Recirculation Region ◽  
Reacting Flow ◽  
Gas Turbine Combustor ◽  
Flow Through ◽  
Flow Field Analysis ◽  
Marine Engineering

Present work is concerned with the flow field analysis inside a marine annular gas turbine combustor under non-reacting as well as reacting flow conditions. Three-dimensional gas turbine combustor of 20-degree sector geometry has been created and meshed using the pre-processor GAMBIT. Flow through the combustor has been simulated using FLUENT code by solving the appropriate governing equations viz. Conservation of mass, momentum and energy. The RNG k-ε turbulence model is used for physical modeling. Combustion has been modeled using the Probability Density Function (PDF) approach. Total pressure loss has been studied for the isothermal as well as reacting flow case. For reacting flow overall pressure loss across the combustor has been evaluated. Keywords: Combustor, Recirculation region, Non-reacting flow. doi: 10.3329/jname.v2i1.2027 Journal of Naval Architecture and Marine Engineering 2(1)(2005) 21-32

scholarly journals The Design and Evaluation of a 14 Stage, 16:1 Pressure Ratio Compressor for an Industrial Gas Turbine

1996 ◽  
Author(s):  
Mohammad R. Saadatmand
Keyword(s):  
Experimental Data ◽  
Gas Turbine ◽  
Rotor Blade ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Suction Surface ◽  
Design Intent ◽  
Flow Through ◽  
Industrial Gas Turbine

The aerodynamic design process leading to the production configuration of a 14 stage, 16:1 pressure ratio compressor for the Taurus 70 gas turbine is described. The performance of the compressor is measured and compared to the design intent. Overall compressor performance at the design condition was found to be close to design intent. Flow profiles measured by vane mounted instrumentation are presented and discussed. The flow through the first rotor blade has been modeled at different operating conditions using the Dawes (1987) three-dimensional viscous code and the results are compared to the experimental data. The CFD prediction agreed well with the experimental data across the blade span, including the pile up of the boundary layer on the corner of the hub and the suction surface. The rotor blade was also analyzed with different grid refinement and the results were compared with the test data.

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.

Effect of Prediffuser Angle on the Static Pressure Recovery in Flow Through Casing-Liner Annulus of a Gas Turbine Combustor at Various Swirl Levels

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Prakash Ghose ◽  
Amitava Datta ◽  
Achintya Mukhopadhyay
Keyword(s):  
Gas Turbine ◽  
Static Pressure ◽  
Numerical Study ◽  
Pressure Recovery ◽  
Gas Turbine Combustor ◽  
Pressure Losses ◽  
Pressure Distributions ◽  
Inlet Swirl ◽  
Flow Through ◽  
The Ideal

A numerical study has been performed in an axisymmetric diffuser followed by a casing-liner annulus of a typical gas turbine combustor to analyze the flow structure and pressure recovery in the geometry. Static pressure recovery in a gas turbine combustor is important to ensure high pressure of air around the liner. However, the irreversible pressure losses reduce the static pressure recovery from the ideal value. The presence of swirl in the flow from compressor and prediffuser geometry before the dump diffuser influences the flow pattern significantly. In this study, flow structures are numerically predicted with different prediffuser angles and inlet swirl levels for different dump gaps. Streamline distributions and pressure plots on the casing and liner walls are analyzed. Static pressure recovery coefficients are obtained from the pressure distributions across the combustor. The effect of dump gap on the static pressure recovery has also been evaluated. It is observed that the best static pressure recovery can be obtained at optimum values of inlet swirl level and prediffuser angle. Dump gap is found to have significant influence on the static pressure recovery only at small prediffuser angle.

Thermoacoustic Modeling of a Gas Turbine Combustor Equipped With Acoustic Dampers

2005 ◽  
Vol 127 (2) ◽  
pp. 372-379 ◽  
Author(s):  
Valter Bellucci ◽  
Bruno Schuermans ◽  
Dariusz Nowak ◽  
Peter Flohr ◽  
Christian Oliver Paschereit
Keyword(s):  
Transfer Function ◽  
Gas Turbine ◽  
Mixture Fraction ◽  
Time Lag ◽  
Multiple Input Multiple Output ◽  
Three Dimensional ◽  
Analytical Models ◽  
Gas Turbine Combustor ◽  
Input Multiple Output ◽  
The Time Domain

In this work, the TA3 thermoacoustic network is presented and used to simulate acoustic pulsations occurring in a heavy-duty ALSTOM gas turbine. In our approach, the combustion system is represented as a network of acoustic elements corresponding to hood, burners, flames and combustor. The multi-burner arrangement is modeled by describing the hood and combustor as Multiple Input Multiple Output (MIMO) acoustic elements. The MIMO transfer function (linking acoustic pressures and acoustic velocities at burner locations) is obtained by a three-dimensional modal analysis performed with a Finite Element Method. Burner and flame analytical models are fitted to transfer function measurements. In particular, the flame transfer function model is based on the time-lag concept, where the phase shift between heat release and acoustic pressure depends on the time necessary for the mixture fraction (formed at the injector location) to be convected to the flame. By using a state-space approach, the time domain solution of the acoustic field is obtained. The nonlinearity limiting the pulsation amplitude growth is provided by a fuel saturation term. Furthermore, Helmholtz dampers applied to the gas turbine combustor are acoustically modeled and included in the TA3 model. Finally, the predicted noise reduction is compared to that achieved in the engine.

Three-Dimensional CFD Analysis of a Gas Turbine Combustor for Medium/Low Heating Value Syngas Fuel

2008 ◽  
Author(s):  
Yan Xiong ◽  
Lucheng Ji ◽  
Zhedian Zhang ◽  
Yue Wang ◽  
Yunhan Xiao
Keyword(s):  
Gas Turbine ◽  
Film Cooling ◽  
Coal Gasification ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Combined Cycle ◽  
Gas Turbine Combustor ◽  
Integrated Gasification Combined Cycle ◽  
Heating Value ◽  
Flamelet Model

Gas turbine is one of the key components for integrated gasification combined cycle (IGCC) system. Combustor of the gas turbine needs to burn medium/low heating value syngas produced by coal gasification. In order to save time and cost during the design and development of a gas turbine combustor for medium/low heating value syngas, computational fluid dynamics (CFD) offers a good mean. In this paper, 3D numerical simulations were carried out on a full scale multi-nozzle gas turbine combustor using commercial CFD software FLUENT. A 72 degrees sector was modeled to minimize the number of cells of the grid. For the fluid flow part, viscous Navier-Stokes equations were solved. The realizable k-ε turbulence model was adopted. Steady laminar flamelet model was used for the reacting system. The interaction between fluid turbulence and combustion chemistry was taken into account by the PDF (probability density function) model. The simulation was performed with two design schemes which are head cooling using film-cooling and impingement cooling. The details of the flow field and temperature distribution inside the two gas turbine combustors obtained could be cited as references for design and retrofit. Similarities were found between the predicted and experimental data of the transition duct exit temperature profile. There is much work yet to be done on modeling validation in the future.

Flow Field Analysis of Pulse Converter Exhaust Manifold of Diesel Engines

2012 ◽  
Vol 468-471 ◽  
pp. 1693-1696
Author(s):  
Wen Jun Zhong ◽  
Zhi Xia He ◽  
Zhao Chen Jiang ◽  
Yun Long Huang
Keyword(s):  
Unsteady Flow ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Region ◽  
Field Analysis ◽  
Exhaust Manifold ◽  
Recirculation Flow ◽  
Pulse Converter ◽  
Flow Field Analysis ◽  
Better Than

A three-dimensional unsteady flow for the pulse converter exhaust manifold of 8-cylinder diesel engine was numerical simulated to get the flow characteristics of the exhaust manifold. Simulation results show that there are strong eddy flows, low pressure closed recirculation flow region in the exhaust manifold. Afterwards the structure optimization of the exhaust manifold with baffle was put forward and then the unsteady flow in the normal exhaust manifold, the exhaust manifold with baffle of 30 degrees and the exhaust manifold of 15 degrees were simulated and analyzed. It is concluded that the exhaust manifold with baffle is better than that without baffle, the recirculation flow region and the pressure loss in the exhaust manifold with baffle of 30 degrees is smaller than in it with baffle of 15 degree and the flow in the former exhaust manifold is much smoother.

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