Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Influence of chemical kinetics on detonation initiating by temperature
  gradients in methane/air   Different simplified and detailed chemical models and their impact on
simulations of combustion regimes initiating by the initial temperature
gradient in methane/air mixtures are studied. The limits of the regimes of
reaction wave propagation depend upon the spontaneous wave speed and the
characteristic velocities of the problem. The present study mainly focus to
identify conditions required for the development a detonation and to compare
the difference between simplified chemical models and detailed chemistry. It is
shown that a widely used simplified chemical schemes, such as one-step,
two-step and other simplified models, do not reproduce correctly the ignition
process in methane/air mixtures. The ignition delay times calculated using
simplified models are in orders of magnitude shorter than the ignition delay
times calculated using detailed chemical models and measured experimentally.
This results in considerably different times when the exothermic reaction
affects significantly the ignition, evolution, and coupling of the spontaneous
reaction wave and pressure waves. We show that the temperature gradient capable
to trigger detonation calculated using detailed chemical models is much
shallower (the size of the hot spot is much larger) than that, predicted by
simulations with simplified chemical models. These findings suggest that the
scenario leading to the deflagration to detonation transition (DDT) may depend
greatly on the chemical model used in simulations and that the Zeldovich
gradient mechanism is not necessary a universal mechanism triggering DDT. The
obtained results indicate that the conclusions derived from the simulations of
DDT with simplified chemical models should be viewed with great caution.

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The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org