Travelling Waves in a Two-Step Chain Branching Model with Heat Loss

2009 ◽  
Vol 4 (3) ◽  
Author(s):  
Harvinder S Sidhu ◽  
V.V. Gubernov ◽  
Geoff Mercer ◽  
A.V. Kolobov ◽  
A.A. Polezhaev ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Numerical Investigation ◽  
Heat Loss ◽  
Combustion Wave ◽  
Travelling Waves ◽  
Chain Branching ◽  
Combustion Waves ◽  
Extinction Limit ◽  
Branching Model ◽  
Loss Parameter

In this paper we undertake a numerical investigation of travelling nonadiabatic combustion waves for the case of a two-step chain branching reaction mechanism. For simplicity we have assumed equal diffusivity of the reactant, radicals and heat. The speed of the combustion wave is analysed for different values of the heat loss parameter. We also determine how the extinction limit depends on the heat loss parameter as well as properties of the fuel.

Multiplicity of Premixed Flames Under the Effect of Heat Loss

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Eman Al-Sarairah ◽  
Chaouki Ghenai ◽  
Ahmed Hachicha
Keyword(s):  
Strain Rate ◽  
Heat Loss ◽  
Combustion Wave ◽  
Premixed Flames ◽  
Lewis Number ◽  
The Other ◽  
Premixed Flame ◽  
Two Dimensional ◽  
Combustion Waves ◽  
Loss Parameter

We investigate numerically the effect of heat loss and strain rate on the premixed flame edges encountered in a two-dimensional counterflow configuration for Lewis number higher than one. Under nonadiabatic conditions, multiple flame edges and multiple propagation speeds (positive and negative) are discussed. Different regions of multiple propagation speeds have been revealed ranging from two to four, depending on the value of the heat loss parameter and Damkohler number, which is inversely proportional to the strain rate. A combustion wave is modeled by connecting a strongly burning flame on one side of the burner to a weakly burning flame on the other side. These combustion waves are changing with increasing Dam number into flame edges with the fact that the strongly burning flame is the dominant.

scholarly journals Oscillatiory combustion waves in a chain branching model

2009 ◽  
Vol 50 ◽  
pp. 1017
Author(s):  
Harvinder Singh Sidhu ◽  
V. V. Gubernov ◽  
A. V. Kolobov ◽  
A. A. Polezhaev ◽  
G. N. Mercer ◽  
...  
Keyword(s):  
Chain Branching ◽  
Combustion Waves ◽  
Branching Model ◽  
A Chain

Period doubling and chaotic transient in a model of chain-branching combustion wave propagation

2010 ◽  
Vol 466 (2121) ◽  
pp. 2747-2769 ◽  
Author(s):  
Vladimir Gubernov ◽  
Andrei Kolobov ◽  
Andrei Polezhaev ◽  
Harvinder Sidhu ◽  
Geoffry Mercer
Keyword(s):  
Wave Propagation ◽  
Hopf Bifurcation ◽  
Combustion Wave ◽  
Period Doubling ◽  
Chaotic Regime ◽  
Bifurcation Parameter ◽  
Chain Branching ◽  
Combustion Waves ◽  
Combustion Wave Propagation ◽  
Parameter Values

The propagation of planar combustion waves in an adiabatic model with two-step chain-branching reaction mechanism is investigated. The travelling combustion wave becomes unstable with respect to pulsating perturbations as the critical parameter values for the Hopf bifurcation are crossed in the parameter space. The Hopf bifurcation is demonstrated to be of a supercritical nature and it gives rise to periodic pulsating combustion waves as the neutral stability boundary is crossed. The increase of the ambient temperature is found to have a stabilizing effect on the propagation of the combustion waves. However, it does not qualitatively change the behaviour of the travelling combustion waves. Further increase of the bifurcation parameter leads to the period-doubling bifurcation cascade and a chaotic regime of combustion wave propagation. The chaotic regime has a transient nature and the combustion wave extinguishes when the bifurcation parameter becomes sufficiently large. For Lewis numbers of fuel close to unity, the parameter regions where pulsating solutions exist become very close to each other and this makes it difficult to experimentally observe the period-doubling. It is shown that the average velocity of pulsating waves is less than the speed of the travelling wave for the same parameter values.

scholarly journals Non-adiabatic combustion waves for general Lewis numbers: wave speed and extinction conditions

2004 ◽  
Vol 46 (1) ◽  
pp. 1-16 ◽  
Author(s):  
A. C. McIntosh ◽  
R. O. Weber ◽  
G. N. Mercer
Keyword(s):  
Activation Energy ◽  
Heat Loss ◽  
Combustion Wave ◽  
Wave Speed ◽  
Energy Analysis ◽  
Lewis Number ◽  
Heat Losses ◽  
Combustion Waves ◽  
Wave Speeds ◽  
Oscillatory Instabilities

AbstractThis paper addresses the effect of general Lewis number and heat losses on the calculation of combustion wave speeds using an asymptotic technique based on the ratio of activation energy to heat release being considered large. As heat loss is increased twin flame speeds emerge (as in the classical large activation energy analysis) with an extinction heat loss. Formulae for the non-adiabatic wave speed and extinction heat loss are found which apply over a wider range of activation energies (because of the nature of the asymptotics) and these are explored for moderate and large Lewis number cases—the latter representing the combustion wave progress in a solid. Some of the oscillatory instabilities are investigated numerically for the case of a reactive solid.

Numerical investigation of the instability for one-dimensional Chapman–Jouguet detonations with chain-branching kinetics

2005 ◽  
Vol 9 (3) ◽  
pp. 385-401 ◽  
Author(s):  
H. D. Ng ◽  
M. I. Radulescu ◽  
A. J. Higgins ◽  
N. Nikiforakis ◽  
J. H. S. Lee
Keyword(s):  
Numerical Investigation ◽  
Chain Branching ◽  
One Dimensional

Analysis of Normal Combustion Waves in CH4-Air System

2014 ◽  
Vol 656 ◽  
pp. 101-109 ◽  
Author(s):  
Daniel Eugeniu Crunteanu ◽  
Dan Racoti ◽  
Corneliu Berbente
Keyword(s):  
Shock Waves ◽  
Algebraic Equation ◽  
Combustion Wave ◽  
Normal Shock ◽  
Combustion Waves ◽  
Conservation Equations ◽  
One Dimensional ◽  
Air System ◽  
The One

In this study one analyses the detonation and deflagration waves starting with Euler one-dimensional conservative equations. We present two methods of computing the normal combustion waves and normal shock waves parameters. The second one, called Cpm method, uses the one dimensional conservation equations system of mass, impulse and energy reduced to an quadratic algebraic equation. Combustion wave ,in CH4-air system is presented as an application.

Effect of heat loss on combustion wave stability

1981 ◽  
Vol 17 (2) ◽  
pp. 177-180 ◽  
Author(s):  
A. P. Aldushin ◽  
S. G. Kasparyan
Keyword(s):  
Heat Loss ◽  
Combustion Wave ◽  
Wave Stability
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