scholarly journals LASER STABILIZATION FOR NEAR ZERO NO{sub x} GAS TURBINE COMBUSTION SYSTEMS

2002 ◽  
Author(s):  
Vivek Khanna
Keyword(s):  
Gas Turbine ◽  
Laser Stabilization ◽  
Gas Turbine Combustion ◽  
Combustion Systems

Review of Hybrid Emissions Prediction Tools and Uncertainty Quantification Methods for Gas Turbine Combustion Systems

2017 ◽  
Author(s):  
Sajjad Yousefian ◽  
Gilles Bourque ◽  
Rory F. D. Monaghan
Keyword(s):  
Uncertainty Quantification ◽  
Gas Turbine ◽  
Kinetic Modelling ◽  
Computational Cost ◽  
Chemical Kinetic ◽  
Design Development ◽  
Deterministic Models ◽  
Prediction Tools ◽  
Gas Turbine Combustion ◽  
Combustion Systems

There is a need for fast and reliable emissions prediction tools in the design, development and performance analysis of gas turbine combustion systems to predict emissions such as NOx, CO. Hybrid emissions prediction tools are defined as modelling approaches that (1) use computational fluid dynamics (CFD) or component modelling methods to generate flow field information, and (2) integrate them with detailed chemical kinetic modelling of emissions using chemical reactor network (CRN) techniques. This paper presents a review and comparison of hybrid emissions prediction tools and uncertainty quantification (UQ) methods for gas turbine combustion systems. In the first part of this study, CRN solvers are compared on the bases of some selected attributes which facilitate flexibility of network modelling, implementation of large chemical kinetic mechanisms and automatic construction of CRN. The second part of this study deals with UQ, which is becoming an important aspect of the development and use of computational tools in gas turbine combustion chamber design and analysis. Therefore, the use of UQ technique as part of the generalized modelling approach is important to develop a UQ-enabled hybrid emissions prediction tool. UQ techniques are compared on the bases of the number of evaluations and corresponding computational cost to achieve desired accuracy levels and their ability to treat deterministic models for emissions prediction as black boxes that do not require modifications. Recommendations for the development of UQ-enabled emissions prediction tools are made.

Validation of Advanced Computational Methods for Determining Flame Transfer Functions in Gas Turbine Combustion Systems

2007 ◽  
Author(s):  
Krzysztof Kostrzewa ◽  
Berthold Noll ◽  
Manfred Aigner ◽  
Joachim Lepers ◽  
Werner Krebs ◽  
...  
Keyword(s):  
System Identification ◽  
Heat Release ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Transfer Functions ◽  
Sound Waves ◽  
Gas Turbine Combustion ◽  
Combustion Systems ◽  
Combustion Processes ◽  
Gas Turbine Burner

The operation envelope of modern gas turbines is affected by thermoacoustically induced combustion oscillations. The understanding and development of active and passive means for their suppression is crucial for the design process and field introduction of new gas turbine combustion systems. Whereas the propagation of acoustic sound waves in gas turbine combustion systems has been well understood, the flame induced acoustic source terms are still a major topic of investigation. The dynamics of combustion processes can be analyzed by means of flame transfer functions which relate heat release fluctuations to velocity fluctuations caused by a flame. The purpose of this paper is to introduce and to validate a novel computational approach to reconstruct flame transfer functions based on unsteady excited RANS simulations and system identification. Resulting time series of velocity and heat release are then used to reconstruct the flame transfer function by application of a system identification method based on Wiener-Hopf formulation. CFD/SI approach has been applied to a typical gas turbine burner. 3D unsteady simulations have been performed and the flame transfer results have been validated by comparison to experimental data. In addition the method has been benchmarked to results obtained from sinusoidal excitations.

A106 Upgraded lineup of KAWASAKI Green Gas Turbine combustion systems(Gas Turbine-2)

2009 ◽  
Vol 2009.1 (0) ◽  
pp. _1-53_-_1-57_
Author(s):  
Shigeki AOKI ◽  
Kiyoshi MATSUMOTO ◽  
Yasushi DOUURA ◽  
Takeo ODA ◽  
Masahiro Ogata ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbine Combustion ◽  
Combustion Systems

Impact of Boundary Conditions on the Reconstructed Flame Transfer Function for Gas Turbine Combustion Systems

2008 ◽  
Author(s):  
Krzysztof Kostrzewa ◽  
Axel Widenhorn ◽  
Berthold Noll ◽  
Manfred Aigner ◽  
Werner Krebs ◽  
...  
Keyword(s):  
Transfer Function ◽  
Boundary Conditions ◽  
Gas Turbine ◽  
Transfer Functions ◽  
Feedback Mechanism ◽  
Pressure Amplitude ◽  
Flame Response ◽  
Gas Turbine Combustion ◽  
Combustion Systems ◽  
The Impact

In order to achieve low levels of pollutants modern gas turbine combustion systems operate in lean and premixed modes. However, under these conditions self-excited combustion oscillations due to a complex feedback mechanism between pressure and heat release fluctuations can be found. These instabilities may lead to uncontrolled high pressure amplitude oscillations which can damage the whole combustor. The flame induced acoustic source terms are still analytically not well described and are a major topic of thermo-acoustic investigations. For the analysis of thermo-acoustic phenomena in gas turbine combustion systems flame transfer functions can be utilized. The purpose of this paper is to introduce and to investigate modeling parameters, which could influence a novel computational approach to reconstruct flame transfer functions known as the CFD/SI method. The flame transfer function estimation is made by application of a system identification method based on Wiener-Hopf formulation. Varying acoustic boundary conditions, combustion models and time resolutions may strongly affect the reconstructed flame response characterizing overall system dynamics. The CFD/SI approach has been applied to a generic gas turbine burner to derive a flame response. 3D unsteady simulations excited with white noise have been performed and the reconstructed flame transfer functions have been validated with experimental data. Moreover, the impact on the reconstructed flame transfer functions because of different boundary condition configurations has been examined.

Interaction Between the Acoustic Pressure Fluctuations and the Unsteady Flow Field Through Circular Holes

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Jochen Rupp ◽  
Jon Carrotte ◽  
Adrian Spencer
Keyword(s):  
Velocity Field ◽  
Flow Field ◽  
Gas Turbine ◽  
Nonlinear Absorption ◽  
Acoustic Pressure ◽  
Pressure Fluctuations ◽  
Type Systems ◽  
Linear And Nonlinear ◽  
Gas Turbine Combustion ◽  
Combustion Systems

Gas turbine combustion systems are prone to thermo-acoustic instabilities, and this is particularly the case for new low emission lean burn type systems. The presence of such instabilities is basically a function of the unsteady heat release within the system (i.e., both magnitude and phase) and the amount of damping. This paper is concerned with this latter process and the potential damping provided by perforated liners and other circular apertures found within gas turbine combustion systems. In particular, the paper outlines experimental measurements that characterize the flow field within the near field region of circular apertures when being subjected to incident acoustic pressure fluctuations. In this way the fundamental process by which acoustic energy is converted into kinetic energy of the velocity field can be investigated. Experimental results are presented for a single orifice located in an isothermal duct at ambient test conditions. Attached to the duct are two loudspeakers that provide pressure fluctuations incident onto the orifice. Unsteady pressure measurements enable the acoustic power absorbed by the orifice to be determined. This was undertaken for a range of excitation amplitudes and mean flows through the orifice. In this way regimes where both linear and nonlinear absorption occur along with the transition between these regimes can be investigated. The key to designing efficient passive dampers is to understand the interaction between the unsteady velocity field, generated at the orifice and the acoustic pressure fluctuations. Hence experimental techniques are also presented that enable such detailed measurements of the flow field to be made using particle image velocimetry. These measurements were obtained for conditions at which linear and nonlinear absorption was observed. Furthermore, proper orthogonal decomposition was used as a novel analysis technique for investigating the unsteady coherent structures responsible for the absorption of energy from the acoustic field.

Large-Eddy Simulations as a Design Tool for Gas Turbine Combustion Systems

AIAA Journal ◽  
2006 ◽  
Vol 44 (4) ◽  
pp. 674-686 ◽  
Author(s):  
S. James ◽  
J. Zhu ◽  
M. S. Anand
Keyword(s):  
Gas Turbine ◽  
Design Tool ◽  
Large Eddy Simulations ◽  
Large Eddy ◽  
Gas Turbine Combustion ◽  
Combustion Systems

The Use of Perforated Damping Liners in Aero Gas Turbine Combustion Systems

2011 ◽  
Author(s):  
Jochen Rupp ◽  
Jon Carrotte ◽  
Michael Macquisten
Keyword(s):  
Pressure Drop ◽  
Flow Field ◽  
Gas Turbine ◽  
Analytical Model ◽  
Operating Conditions ◽  
Acoustic Energy ◽  
Fuel Injector ◽  
Flame Tube ◽  
Gas Turbine Combustion ◽  
Combustion Systems

This paper considers the use of perforated porous liners for the absorption of acoustic energy within aero style gas turbine combustion systems. The overall combustion system pressure drop means that the porous liner (or ‘damping skin’) is typically combined with a metering skin. This enables most of the mean pressure drop, across the flame tube, to occur across the metering skin with the porous liner being exposed to a much smaller pressure drop. In this way porous liners can potentially be designed to provide significant levels of acoustic damping, but other requirements (e.g. cooling, available space envelope etc) must also be considered as part of this design process. A passive damper assembly was incorporated within an experimental isothermal facility that simulated an aero-engine style flame tube geometry. The damper was therefore exposed to the complex flow field present within an engine environment (e.g. swirling efflux from a fuel injector, coolant film passing across the damper surface etc.). In addition, plane acoustic waves were generated using loudspeakers so that the flow field was subjected to unsteady pressure fluctuations. This enabled the performance of the damper, in terms of its ability to absorb acoustic energy, to be evaluated. To complement the experimental investigation a simplified 1D analytical model was also developed and validated against the experimental results. In this way not only was the performance of the acoustic damper evaluated, but also the fundamental processes responsible for this measured performance could be identified. Furthermore the validated analytical model also enabled a wide range of damping geometry to be assessed for a range of operating conditions. In this way damper geometry can be optimized (e.g. for a given space envelope) whilst the onset of non-linear absorption (and hence the potential to ingest hot gas) can also be identified.

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