scholarly journals Measurement of Transfer Matrices and Source Terms of Premixed Flames

2002 ◽  
Vol 124 (2) ◽  
pp. 239-247 ◽  
Author(s):  
C. O. Paschereit ◽  
B. Schuermans ◽  
W. Polifke ◽  
O. Mattson
Keyword(s):  
Gas Turbine ◽  
Transfer Matrix ◽  
Acoustic Waves ◽  
Combustion Process ◽  
The State ◽  
Acoustic Properties ◽  
Analytical Models ◽  
State Variables ◽  
Thermoacoustic Properties ◽  
Gas Turbine Burner

An experimental method to determine the thermoacoustic properties of a gas turbine combustor using a lean-premixed low emission swirl stabilized burner is presented. To model thermoacoustic oscillations, a combustion system can be described as a network of acoustic elements, representing for example fuel and air supply, burner and flame, combustor, cooling channels, suitable terminations, etc. For most of these elements, simple analytical models provide an adequate description of their thermoacoustic properties. However, the complex response of burner and flame (involving a three-dimensional flow field, recirculation zones, flow instabilities, and heat release) to acoustic perturbations has—at least in a first step—to be determined by experiment. In our approach, we describe the burner as an active acoustical two-port, where the state variables pressure and velocity at the inlet and the outlet of the two port are coupled via a four element transfer matrix. This approach is similar to the “black box” theory in communication engineering. To determine all four transfer matrix coefficients, two test states, which are independent in the state vectors, have to be created. This is achieved by using acoustic excitation by loudspeakers upstream and downstream of the burner, respectively. In addition, the burner might act as an acoustic source, emitting acoustic waves due to an unsteady combustion process. The source characteristics were determined by using a third test state, which again must be independent from the two other state vectors. In application to a full size gas turbine burner, the method’s accuracy was tested in a first step without combustion and the results were compared to an analytical model for the burner’s acoustic properties. Then the method was used to determine the burner transfer matrix with combustion. An experimental swirl stabilized premixed gas turbine burner was used for this purpose. The treatment of burners as acoustic two-ports with feedback including a source term and the experimental determination of the burner transfer matrix is novel.

scholarly journals Measurement of Transfer Matrices and Source Terms of Premixed Flames

1999 ◽  
Author(s):  
Christian Oliver Paschereit ◽  
Bruno Schuermans ◽  
Wolfgang Polifke ◽  
Oscar Mattson
Keyword(s):  
Gas Turbine ◽  
Transfer Matrix ◽  
Acoustic Waves ◽  
Combustion Process ◽  
The State ◽  
Acoustic Properties ◽  
Analytical Models ◽  
State Variables ◽  
Thermoacoustic Properties ◽  
Gas Turbine Burner

An experimental method to determine the thermoacoustic properties of a gas turbine combustor using a lean-premixed low emission swirl stabilized burner is presented. To model thermoacoustic oscillations, a combustion system can be described as a network of acoustic elements, representing for example fuel and air supply, burner and flame, combustor, cooling channels, suitable terminations, etc. For most of these elements, simple analytical models provide an adequate description of their thermoacoustic properties. However, the complex response of burner and flame (involving a three-dimensional flow field, recirculation zones, flow instabilities and heat release) to acoustic perturbations has — at least in a first step — to be determined by experiment. In our approach, we describe the burner as an active acoustical two-port, where the state variables pressure and velocity at the inlet and the outlet of the two port are coupled via a four element transfer matrix. This approach is similar to the “black box” theory in communication engineering. To determine all four transfer matrix coefficients, two test states, which are independent in the state vectors, have to be created. This is achieved by using acoustic excitation by loudspeakers upstream and downstream of the burner, respectively. In addition, the burner might act as an acoustic source, emitting acoustic waves due to an unsteady combustion process. The source characteristics were determined by using a third test state, which again must be independent from the two other state vectors. In application to a full size gas turbine burner, the method’s accuracy was tested in a first step without combustion and the results were compared to an analytical model for the burner’s acoustic properties. Then the method was used to determine the burner transfer matrix with combustion. An experimental swirl stabilized premixed gas-turbine burner was used for this purpose. The treatment of burners as acoustic two-ports with feedback including a source term and the experimental determination of the burner transfer matrix is novel.

scholarly journals Investigation of the Thermoacoustic Characteristics of a Lean Premixed Gas Turbine Burner

1998 ◽  
Author(s):  
Christian Oliver Paschereit ◽  
Wolfgang Polifke
Keyword(s):  
Gas Turbine ◽  
Transfer Matrix ◽  
Acoustic Properties ◽  
Analytical Models ◽  
State Variables ◽  
Combustion Chambers ◽  
Cooling Channels ◽  
Air Supply ◽  
Element Transfer ◽  
Gas Turbine Burner

To model thermoacoustic oscillations, a combustion system can be described as a network of acoustic elements, representing for example fuel and air supply, burner and flame, combustor, cooling channels, suitable terminations, etc. For most of these elements, simple analytical models provide an adequate description of their thermoacoustic properties. However, the complex response of burner and flame to acoustic perturbations has — at least in a first step — to be determined by experiment. In our approach, we describe the burner as an active acoustical two-port, where the state variables pressure and velocity at the inlet and the outlet are coupled via a four element transfer matrix. This approach is similar to the “black box” theory in communication engineering. To determine ail four coefficients, two independent test states have to be created. This is achieved by using acoustic sources upstream and downstream of the burner, respectively. In application to a full size gas turbine burner, the method’s accuracy was tested in a first step without combustion and the results were compared to an analytical model for the burner’s acoustic properties. Then the method was used to determine the burner transfer matrix with combustion and to investigate the influence of various parameters such as acoustic amplitude and equivalence ratio. The treatment of burners as acoustic two-port with feedback used to model the thermoacoustic behavior of combustion chambers and the experimental determination of the burner transfer matrix is novel.

Prediction of Acoustic Pressure Spectra in Combustion Systems Using Swirl Stabilized Gas Turbine Burners

2000 ◽  
Author(s):  
Bruno B. H. Schuermans ◽  
Wolfgang Polifke ◽  
Christian Oliver Paschereit ◽  
Jan H. van der Linden
Keyword(s):  
Frequency Response ◽  
Gas Turbine ◽  
Transfer Matrix ◽  
Source Term ◽  
Swirling Flow ◽  
Homogeneous System ◽  
Acoustic Properties ◽  
Variable Cross ◽  
Acoustic Oscillations ◽  
Cross Sectional

A method to predict pressure spectra of gas turbine combustion chambers with premixed, turbulent, swirl-stabilized flames is presented. The combustion system is represented as a network of acoustic elements, where each element is characterized by its transfer matrix. Analytic equations can be derived for most of the elements in such a network (e.g. ducts with variable cross-sectional area, sudden area changes etc.). However, the description of the acoustic properties of the burner and flame still require experimental input because of the complex interaction between the turbulent swirling flow, fuel supply and unsteady heat release. Acoustic excitation can be applied up-, and downstream of the burner in order to determine the transfer matrix of burner and flame. Due to the turbulent flow and combustion, the flame itself may also act as an independent source of sound. Thus, the burner does not only transmit and reflect incoming signals, but generates its own signal, independent of the acoustic state upstream and downstream. This quantity, the source-term, has been determined experimentally as well. Having determined the acoustic properties of all the elements (either analytically or by experiment) the thermoacoustic network can be built up. The frequency spectrum of the acoustic oscillations can then be investigated by solving the non-homogeneous system of equations, where the inhomogeneties are due to the source term of the flame. Because of the network approach, the influence of different acoustic boundary conditions on the frequency response has been determined. Application of the method to an atmospheric combustion test-rig with a gas turbine burner showed that the predicted frequency response and stability were in good agreement with experimental data.

COMBUSTION INSTABILITY ANALYSIS OF A MODEL GAS TURBINE COMBUSTOR WITH CLOSED ACOUSTIC BOUNDARIES AT BOTH ENDS

2011 ◽  
Vol 19 (03) ◽  
pp. 231-238
Author(s):  
DONG-JIN CHA
Keyword(s):  
Gas Turbine ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Combustion Instability ◽  
Combustion Process ◽  
Side Branch ◽  
Combustion System ◽  
Efficient Operation ◽  
Gas Turbine Combustors

Combustion instability is a major issue in designing gas turbine combustors for an efficient operation with low emissions. Combustion instability is induced by the interaction of the unsteady heat release of the combustion process and changes in the acoustic pressure in the combustion chamber. In an effort to develop a technique to predict self-excited combustion instability of gas turbine combustors, a new stability analysis method based on the transfer matrix method was developed. The method views the combustion system as a one-dimensional acoustic system with a side branch and describes the heat source as the input to the system. This approach makes it possible to use not only the advantages of the transfer matrix method but also well established classic control theories. The approach is applied to a gas turbine combustion system, which shows the validity and effectiveness of the approach.

Auto-Ignition in a Gas Turbine Burner at Elevated Temperature

2003 ◽  
Author(s):  
Martin Brandt ◽  
Wolfgang Polifke ◽  
Blazenko Ivancic ◽  
Peter Flohr ◽  
Bettina Paikert
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Cfd Simulation ◽  
Combustion Process ◽  
Reaction Rates ◽  
Operating Conditions ◽  
Lookup Table ◽  
Reacting Flow ◽  
Gas Turbine Burner

Many facilities, e.g. reheat gas turbines or internal combustion engines, are operated with hydrocarbon fuels at elevated preheat temperatures such that conditions may be encountered where the flame is not stabilized by flame propagation, but by self-ignition. A model for turbulent reacting flow in this combustion regime has been developed, based on an ignition indicator representing the evolution of a pool of chemical intermediates. Interactions between turbulence and chemistry are taken into account using a new Monte-Carlo joint PDF approach. The joint PDF is not approximated by an analytical function, but by representative ensembles of particles, which are generated with a biased random number generator. Mean reaction rates are computed from the first and second moments — including co-variances — of those variables which describe the thermochemical state of the mixture. It is possible to calculate mean reaction rates in a pre-processing step and store them in a lookup-table table for use in a subsequent CFD simulation, making the approach very efficient. The model has been implemented in a CFD code and validated against an industrial gas turbine burner configuration. It has been found that the model describes the combustion process for a range of operating conditions with good accuracy.

scholarly journals A Transfer-Matrix-Perturbation Approach to the Dynamics of Chains of Nonlinear Sliding Beams

2005 ◽  
Vol 128 (2) ◽  
pp. 190-196 ◽  
Author(s):  
Angelo Luongo ◽  
Francesco Romeo
Keyword(s):  
Transfer Matrix ◽  
Harmonic Balance Method ◽  
The State ◽  
Single Element ◽  
Perturbation Approach ◽  
Matrix Perturbation ◽  
State Variables ◽  
Field Equations ◽  
Axial Forces ◽  
Nonlinear Shear

Chains of nonlinear shear indeformable beams with distributed mass, resting on movable supports, are considered. To determine the dynamic response of the system, the transfer-matrix approach is merged with the harmonic balance method and a perturbation method, thereby transforming the original space-temporal continuous problem into a discrete one-dimensional map xk+1=F(xk) expressed in terms of the state variables xk at the interface between adjacent beams. Such transformation does not imply any discretization, because it is obtained by integrating the single-element field equations. The state variables consist of both first-order variables, namely, transversal displacement and couples, and second-order variables, which are longitudinal displacement and axial forces. Therefore, while the linear problem is monocoupled, the nonlinear one becomes multicoupled. The procedure is applied to determine frequency-response relationship under free and forced vibrations.

Investigation of the Degradation Behaviors of a Gas Turbine Burner made of an Inconel 738LC Superalloy

2013 ◽  
Vol 51 (3) ◽  
pp. 159-168 ◽  
Author(s):  
Je Hyun Lee ◽  
Ta Kwan Woo ◽  
Hyun Uk Hong ◽  
Kyung Mi Park ◽  
Hee Soo Kim ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Degradation Behaviors ◽  
Inconel 738Lc ◽  
Gas Turbine Burner

Solidification Cracking in Manually TIG-Brazed T/C Installations of Novel AM Gas Turbine Burner Component

2019 ◽  
Vol 56 (12) ◽  
pp. 813-820
Author(s):  
A. Neidel ◽  
T. Gädicke ◽  
S. Riesenbeck ◽  
E. Wöhl
Keyword(s):  
Gas Turbine ◽  
Solidification Cracking ◽  
Gas Turbine Burner

Method of tribodiagnostics of d-30KU engines/KP with the use of a microwave plasma complex: results of metrological examination and analysis of the accuracy

2020 ◽  
pp. 22-29
Author(s):  
A. Bogoyavlenskiy ◽  
A. Bokov
Keyword(s):  
Gas Turbine ◽  
Microwave Plasma ◽  
Technical Condition ◽  
The State ◽  
Turbine Engines ◽  
Metrological Examination ◽  
Gas Turbine Engines ◽  
High Frequency Plasma ◽  
Frequency Plasma ◽  
Primary Standards

The article contains the results of the metrological examination and research of the accuracy indicators of a method for diagnosing aircraft gas turbine engines of the D30KU/KP family using an ultra-high-frequency plasma complex. The results of metrological examination of a complete set of regulatory documents related to the diagnostic methodology, and an analysis of the state of metrological support are provided as well. During the metrological examination, the traceability of a measuring instrument (diagnostics) – an ultrahigh-frequency plasma complex – is evaluated based on the scintillation analyzer SAM-DT-01–2. To achieve that, local verification schemes from the state primary standards of the corresponding types of measurements were built. The implementation of measures to eliminate inconsistencies identified during metrological examination allows to reduce to an acceptable level the metrological risks of adverse situations when carrying out aviation activities in industry and air transportation. In addition, the probability of occurrence of errors of the first and second kind in the technological processes of tribodiagnostics of aviation gas turbine engines is reduced when implementing a method that has passed metrological examination in real practice. At the same time, the error in determining ratings and wear indicators provides acceptable accuracy indicators and sufficient reliability in assessing the technical condition of friction units of the D-30KP/KP2/KU/KU-154 aircraft engines.

Non Linear State and Parameters Estimation in Chemical Processes: Analysis and Improvement of Three Estimation Structures Applied to a CSTR

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Héctor Botero ◽  
Hernán Álvarez
Keyword(s):  
Parameter Estimation ◽  
Chemical Process ◽  
Chemical Processes ◽  
The State ◽  
Convergence Speed ◽  
Parameters Estimation ◽  
State Variables ◽  
Input Output ◽  
On Line ◽  
Linear State

This paper proposes a new composite observer capable of estimating the states and unknown (or changing) parameters of a chemical process, using some input-output measurements, the phenomenological based model and other available knowledge about the process. The proposed composite observer contains a classic observer (CO) to estimate the state variables, an observer-based estimator (OBE) to obtain the actual values of the unknown or changing parameters needed to tune the CO, and an asymptotic observer (AO) to estimate the states needed as input to the OBE. The proposed structure was applied to a CSTR model with three state variables. With the proposed structure, the concentration of reactants and other CSTR parameters can be estimated on-line if the reactor and jacket temperatures are known. The procedure for the design of the proposed structure is simple and guarantees observer convergence. In addition, the convergence speed of state and parameter estimation can be adjusted independently.

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