Numerical Study of Curved Flames under Confinement
作者:
M. A. L1Berman,,
V. V. Bychkov,
S. M. Golberg,
L. E. Eriksson,
期刊:
Combustion Science and Technology
(Taylor Available online 1998)
卷期:
Volume 136,
issue 1-6
页码: 221-251
ISSN:0010-2202
年代: 1998
DOI:10.1080/00102209808924172
出版商: Taylor & Francis Group
关键词: Hydrodynamic flame instability;acoustic waves;activated liquid phase reactions;shocks
数据来源: Taylor
摘要:
Dynamics of laminar flames in closed tubes is studied by means of two-dimensional numerical simulations taking into account thermal conduction, fuel diffusion, viscosity and chemical kinetics. Development of the hydrodynamic instability of a flame front is investigated for flames with chemical reactions of the first and the third order. We found that for a flame with the first order reaction the hydrodynamic instbility is strongly reduced or even suppressed in sufficiently short tubes. Unlike this, in the case of a flame with the third order reaction the instability is enhanced due to significant increase of the normal velocity of the planar flame under confinement. The instability development for flames of both first and third order reactions is strongly affected by acoustic waves generated by the flame in a closed chamber. Particularly, a weak shock colliding with the flame front may lead to temporary stabilization of the flame instability. On the contrary,when flame comes to the end of the tube the acoustic waves may cause significant increase of the flame instability. We studied a possibility of the detonation ignition ahead of the flame front as well. We found that the detonation can be ignited at the far end of the tube by the weak shocks and sound waves generated by the flame in a closed tube. Triggering of the detonation ahead of the flame propagating in a closed tube is related to the knock problem in spark-ignition engines.
点击下载:
PDF (770KB)
返 回