Large Eddy Simulation of a Swirling Flame Response to Swirl Modulation With Impact on the Combustion Stability

2005 ◽  
Author(s):  
Christophe Duwig ◽  
Robert Szasz ◽  
Laszlo Fuchs ◽  
Christian Troger
Keyword(s):  
Large Eddy Simulation ◽  
Combustion Stability ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Flame Response ◽  
Swirling Flame

Large-Eddy Simulation and Linear Acoustic Analysis of a Diffusion Swirling Flame Under Forcing and Self-Excitation

2016 ◽  
Author(s):  
Man Zhang
Keyword(s):  
Large Eddy Simulation ◽  
Acoustic Analysis ◽  
Dynamic Pressure ◽  
Pressure Oscillation ◽  
Acoustic Method ◽  
Flame Stabilization ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Flame Response ◽  
Swirling Flame

A diffusion swirling flame under external forcing and self-excitation within a single swirler combustor have been studied in this paper with the large-eddy simulation and linear acoustic method. The combustor features pre-vaporized kerosene as the fuel, a single radial air swirler for flame stabilization and a square cross section chamber with adjustable length. Firstly, self-sustained pressure oscillation has been achieved by using of a chocked nozzle on the chamber outlet with large-eddy simulation. Dynamic pressure oscillations are analyzed in frequency domain through Fast Fourier Transform. The major pressure oscillation is identified as the 1st order longitudinal mode of the chamber. Further, the same frequency in the form of harmonic velocity oscillation is imposed on the inlet of the combustor while the chamber length has been changed. Based on this approach, a comparative study of the flame response with different excitation method but same frequency is carried out. In both self-excited and forced cases, global and local flame responses as well as Rayleigh index have been analyzed and compared. With the flame response function, the excited acoustic modes under the influence of dynamic heat release have been predicted with linear acoustic method and compared with the results obtained from large-eddy simulation. Results show that the flame response presents a great difference in the spacial distribution with different excitation approaches. Thermo-acoustic interaction distributes along the flame front with the expansion of the flame under self-excitation while it damps with the acoustic propagating downstream under forcing condition. As the ratio of flame length to acoustic wave length could not be neglected for the diffusion swirling flame, the global flame response under forcing cannot represent the local response feature of the flame accurately, thus influencing the instability prediction.

Effects of confinement on premixed turbulent swirling flame using large Eddy simulation

2013 ◽  
Vol 17 (6) ◽  
pp. 1003-1019 ◽  
Author(s):  
K.-J. Nogenmyr ◽  
H. J. Cao ◽  
C. K. Chan ◽  
R. K. Cheng
Keyword(s):  
Large Eddy Simulation ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Swirling Flame

Large-Eddy Simulation of Acoustic Flame Response to High-Frequency Transverse Excitations

AIAA Journal ◽  
2019 ◽  
Vol 57 (1) ◽  
pp. 327-340
Author(s):  
V. Sharifi ◽  
A. M. Kempf ◽  
C. Beck
Keyword(s):  
Large Eddy Simulation ◽  
High Frequency ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Flame Response

scholarly journals Large Eddy Simulation of Premixed Stratified Swirling Flame Using the Finite Rate Chemistry Approach

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Yinli Xiao ◽  
Zhengxin Lai ◽  
Wenyan Song
Keyword(s):  
Large Eddy Simulation ◽  
Large Scale ◽  
Swirling Flow ◽  
Flame Surface ◽  
Reactor Model ◽  
Finite Rate ◽  
Eddy Simulation ◽  
Major Species ◽  
Large Eddy ◽  
Swirling Flame

Large eddy simulations of a stratified swirling flow of a Cambridge swirl burner for both nonreacting and reacting cases are conducted using a finite rate chemistry approach represented by a partially stirred reactor model. The large eddy simulation predictions are compared with experimental measurements for velocity, temperature, and concentrations of major species. The agreement is found in overall trend of velocity prediction, but temperature and concentration of major species show slight discrepancies in the central region. Two reduced chemical mechanisms are examined in the present paper with the objective of assessing their capabilities in predicting swirling flame characteristics, and the distinct difference using two mechanisms is found in CO distribution profiles, which is considered the consequence of different kinetics of CO-CO2 equilibrium. Flow structures are qualitatively and quantitatively analyzed with numerical results. Large-scale vortex structures and precession motions are observed in both nonreacting and reacting cases. Frequency of vortex shedding is identified from the point data of instantaneous velocity in the discharging stream-induced shear layer. On this basis, the intensity and frequency of precession motion are shown to be enhanced in the presence of combustion. Large-scale wrinkling of the flame surface is resolved and characterized in the flame zone, and the effect of mixture stratification is then further discussed.

scholarly journals High-Fidelity Multiphysics Simulation of a Confined Premixed Swirling Flame Combining Large-Eddy Simulation, Wall Heat Conduction and Radiative Energy Transfer

2017 ◽  
Author(s):  
Chai Koren ◽  
Ronan Vicquelin ◽  
Olivier Gicquel
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Large Eddy Simulation ◽  
Wall Temperature ◽  
Radiative Heat Transfer ◽  
Conjugate Heat Transfer ◽  
Radiative Heat ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Swirling Flame

A multi-physics simulation combining large-eddy simulation, conjugate heat transfer and radiative heat transfer is used to predict the wall temperature field of a confined premixed swirling flame operating under atmospheric pressure. The combustion model accounts for the effect of enthalpy defect on the flame structure whose stabilization is here sensitive to the wall heat losses. The conjugate heat transfer is accounted for by solving the heat conduction within the combustor walls and with the Hybrid-Cell Neumann-Dirichlet coupling method, enabling to dynamically adapt the coupling period. The exact radiative heat transfer equation is solved with an advanced Monte Carlo method with a local control of the statistical error. The coupled simulation is carried out with or without accounting for radiation. Excellent results for the wall temperature are achieved by the fully coupled simulation which are then further analyzed in terms of radiative effects, global energy budget and fluctuations of wall heat flux and temperature.

Large-Eddy Simulation of Turbulent Combustion in Multi Combustors for L30A Gas Turbine Engine

2015 ◽  
Author(s):  
Kohshi Hirano ◽  
Yoshiharu Nonaka ◽  
Yasuhiro Kinoshita ◽  
Masaya Muto ◽  
Ryoichi Kurose
Keyword(s):  
Numerical Analysis ◽  
Large Eddy Simulation ◽  
Swirling Flow ◽  
Flame Temperature ◽  
Computational Cost ◽  
Combustion Stability ◽  
Outlet Temperature ◽  
Eddy Simulation ◽  
Variable Approach ◽  
Large Eddy

When designing a combustor, numerical analysis should be used to effectively predict different performances, such as flame temperature, emission, and combustion stability. However, even with the use of numerical analysis, several problems cannot be solved by investigating single combustors because, in an actual engine, interactions occur between multiple combustors. Therefore, to evaluate the detailed phenomenon in an actual combustor, the interactions between all combustors should be considered in any numerical analysis. On the other hand, a huge amount of computational cost is required for this type of analysis. Here a large-eddy simulation employing a flamelet/progress variable approach is applied to the numerical analysis of industrial combustors. The combustor used for this study is the L30A from Kawasaki Heavy Industries, Ltd. Computations are conducted with a supercomputer (referred to as the “K-computer”) in the RIKEN Advanced Institute for Computational Science. All combustors in the L30A engine (from the compressor outlet to the turbine inlet) are simulated, including the fuel manifold. This engine has eight can combustors that are connected through the fuel manifold and compressed air housing unit. The total number of elements is approximately 140 million. The flow patterns for each combustor are similar in all cans. A swirling flow from the main burner is formed and accelerated by the supplemental burner. There is a high-temperature region before the supplemental burner. The flow field and temperature distribution in an actual combustor interacting with other combustor cans are simulated adequately. The mass flow rate of the air and those of the fuels are distributed equally for each can. Therefore, the outlet temperature difference for each can is also very small.

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