Nonlinear combustion instability analysis based on the flame describing function applied to turbulent premixed swirling flames

2011 ◽  
Vol 158 (10) ◽  
pp. 1980-1991 ◽  
Author(s):  
P. Palies ◽  
D. Durox ◽  
T. Schuller ◽  
S. Candel
Keyword(s):  
Combustion Instability ◽  
Describing Function ◽  
Instability Analysis ◽  
Swirling Flames ◽  
Flame Describing Function ◽  
Turbulent Premixed

scholarly journals Combining a Helmholtz solver with the flame describing function to assess combustion instability in a premixed swirled combustor

2013 ◽  
Vol 160 (9) ◽  
pp. 1743-1754 ◽  
Author(s):  
Camilo Fernando Silva ◽  
Franck Nicoud ◽  
Thierry Schuller ◽  
Daniel Durox ◽  
Sebastien Candel
Keyword(s):  
Combustion Instability ◽  
Describing Function ◽  
Flame Describing Function

Analysis for Combustion Instability and Stabilization Characteristics in a Swirled Premixed Combustor With a Slotted Plate

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Seungtaek Oh ◽  
Jaehyeon Kim ◽  
Yongmo Kim
Keyword(s):  
Neural Network ◽  
Combustion Instability ◽  
Perforated Plate ◽  
Frequency Range ◽  
Describing Function ◽  
Extended Range ◽  
Average Absorption Coefficient ◽  
New Methodologies ◽  
Slotted Plate ◽  
Flame Describing Function

In this study, new methodologies are introduced to analyze combustion instability in a lab-scale swirled combustor. First, with the help of radial basis function neural network (RBFNN), the flame describing function (FDF) is effectively modeled from a limited number of experimental data. This neural-network-based FDF method is able to generate more refined FDF data in an extended range. In addition, instead of a perforated plate with round holes, a slotted plate is utilized as a stabilization device. In this approach, the acoustic impedance of a slotted plate is modeled by the Dowling approach, and the dimensions of a slotted plate are optimized by simulated annealing (SA) algorithm to get the highest average absorption coefficient in a given frequency range. The present RBFNN-based FDF approach yields the reasonably good agreements with the measurements in terms of the limit-cycle velocity perturbation ratio and resonant frequency. It is also found that a slotted plate optimized by SA algorithm is quite effective to attenuate combustion instability. Numerical results obtained in this study confirm that these new methodologies are quite reliable and widely applicable for the analysis of combustion instability encountered in practical combustion systems.

Identification of the Flame Describing Function of a Premixed Swirl Flame from LES

2012 ◽  
Vol 184 (7-8) ◽  
pp. 888-900 ◽  
Author(s):  
H. J. Krediet ◽  
C. H. Beck ◽  
W. Krebs ◽  
S. Schimek ◽  
C. O. Paschereit ◽  
...  
Keyword(s):  
Describing Function ◽  
Flame Describing Function ◽  
Swirl Flame

scholarly journals Flame Dynamics Intermittency in the Bi-Stable Region Near a Subcritical Hopf Bifurcation

2017 ◽  
Author(s):  
D. Ebi ◽  
A. Denisov ◽  
G. Bonciolini ◽  
E. Boujo ◽  
N. Noiray
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Acoustic Pressure ◽  
Oscillation Amplitude ◽  
Stable Region ◽  
Describing Function ◽  
Acoustic Damping ◽  
Intermittent Behavior ◽  
Flame Describing Function

We report experimental evidence of thermoacoustic bi-stability in a lab-scale turbulent combustor over a well-defined range of fuel-air equivalence ratios. Pressure oscillations are characterized by an intermittent behavior with “bursts”, i.e. sudden jumps between low and high amplitudes occurring at random time instants. The corresponding probability density functions of the acoustic pressure signal show clearly separated maxima when the burner is operated in the bi-stable region. A flame describing function, which links acoustic pressure to heat release rate fluctuations, is estimated at the modal frequency from simultaneously recorded flame chemiluminescence and acoustic pressure. The representation of its statistics is new and particularly informative. It shows that this describing function is characterized, in average, by a nearly constant gain and by a significant drift of the phase as function of the oscillation amplitude. This finding suggests that the bi-stability does not result from an amplitude-dependent balance between flame gain and acoustic damping, but rather from the non-constant phase difference between the acoustic pressure and the coherent fluctuations of heat release rate.

Combustion instability analysis on a partially premixed swirl combustor by thermoacoustic experiments and modeling

Energy ◽  
2020 ◽  
Vol 211 ◽  
pp. 118884
Author(s):  
Rongjun Zhu ◽  
Deng Pan ◽  
Chenzhen Ji ◽  
Tong Zhu ◽  
Pengpeng Lu ◽  
...  
Keyword(s):  
Combustion Instability ◽  
Instability Analysis ◽  
Swirl Combustor ◽  
Partially Premixed
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