Numerical Investigation of Reaction Front Propagation in Pressed-column Pyrotechnic Time-delay Devices

2011 ◽  
Author(s):  
Hobin Lee ◽  
Chris Bulian ◽  
Sara Claxton
Keyword(s):  
Time Delay ◽  
Numerical Investigation ◽  
Reaction Front ◽  
Front Propagation

LEEM and selected-area LEED studies of reaction front propagation

1993 ◽  
Vol 287-288 ◽  
pp. A380
Author(s):  
B. Rausenberger ◽  
W. Świȩch ◽  
W. Engel ◽  
A.M. Bradshaw ◽  
E. Zeitler
Keyword(s):  
Reaction Front ◽  
Front Propagation

Detonation development from a hot spot in methane/air mixtures: Effects of kinetic models

2020 ◽  
pp. 146808742094461
Author(s):  
Jingyi Su ◽  
Peng Dai ◽  
Zheng Chen
Keyword(s):  
Natural Gas ◽  
Kinetic Models ◽  
Reaction Front ◽  
Internal Combustion Engines ◽  
Hot Spot ◽  
Thermal Sensitivity ◽  
Front Propagation ◽  
Low Carbon ◽  
Promising Alternative ◽  
Detonation Development

Natural gas is a promising alternative fuel which can be used in internal combustion engines to achieve low carbon emission and high thermal efficiency. However, at high compression ratio, super-knock due to detonation development might occur. In this study, the autoignitive reaction front propagation and detonation development from a hot spot were investigated numerically and the main component of natural gas, methane, was considered. The objective is to assess the performance of different kinetic models in terms of predicting hot spot–induced detonation development in methane/air mixtures. First, simulations for the constant-volume homogeneous ignition in a stoichiometric methane/air mixture were conducted. The ignition delay time, excitation time, critical temperature gradient, thermal sensitivity and reduced activation energy predicted by different kinetic models were obtained and compared. It was found that there are notable discrepancies among the predictions by different kinetic models. Then, hundreds of one-dimensional simulations were conducted for detonation development from a hot spot in a stoichiometric CH4/air mixture. Different autoignition modes were identified and the detonation regimes were derived based on the peak pressure and reaction front propagation speed. It was found that even at the same conditions, different propagation modes can be predicted by different kinetic models. The broadest detonation development regime was predicted by the reduced GRI mechanism, while a relatively narrow regime was predicted by the recent kinetic models such as FFCM-1 and Aramco 3.0. The present results indicate that super-knock prediction strongly depends on the kinetic model used in simulations. Therefore, significant efforts should be devoted to the development and validation of kinetic models for natural gas at engine conditions.

LEEM and selected-area LEED studies of reaction front propagation

1993 ◽  
Vol 287-288 ◽  
pp. 235-240 ◽  
Author(s):  
B. Rausenberger ◽  
W. Świȩch ◽  
W. Engel ◽  
A.M. Bradshaw ◽  
E. Zeitler
Keyword(s):  
Reaction Front ◽  
Front Propagation

Modes of reaction front propagation from hot spots

2003 ◽  
Vol 133 (1-2) ◽  
pp. 63-74 ◽  
Author(s):  
X.J. Gu ◽  
D.R. Emerson ◽  
D. Bradley
Keyword(s):  
Hot Spots ◽  
Reaction Front ◽  
Front Propagation

scholarly journals Termite pyrotechnic compositions of iron and alkaline earth metals peroxides

2020 ◽  
pp. 55-72
Author(s):  
Andrzej Wojewódka ◽  
Marcin Gerlich
Keyword(s):  
Time Delay ◽  
Solid State ◽  
Alkaline Earth ◽  
Front Propagation ◽  
Xrd Analysis ◽  
Propagation Rate ◽  
Alkaline Earth Metals ◽  
Pyrotechnic Compositions ◽  
Iron Based ◽  
Delay Elements

The fallowing article presents the combustion studies of Fe/alkaline earth metals peroxides composition. It contains a literature review and the results of own research, which aim is to determine the possibility of using iron-based thermite compositions in time delay elements. The article focuses on the investigation of combustion front propagation rate as a function of a pressing load, the iron content and the purity of used oxidants. The DSC, TG and XRD analysis confirmed that reactions in this system occurs mainly in the solid state.

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