Type
ArticleKAUST Department
Mechanical Engineering ProgramClean Combustion Research Center
Date
2012-10-13Online Publication Date
2012-10-13Print Publication Date
2012-09Permanent link to this record
http://hdl.handle.net/10754/562312
Metadata
Show full item recordAbstract
Measurements of turbulent burning velocities in fan-stirred explosion bombs show an initial linear increase with the fan speed and RMS turbulent velocity. The line then bends over to form a plateau of high values around the maximum attainable burning velocity. A further increase in fan speed leads to the eventual complete quenching of the flame due to increasing localised extinctions because of the flame stretch rate. The greater the Markstein number, the more readily does flame quenching occur. Flame propagation along a duct closed at one end, with and without baffles to increase the turbulence, is subjected to a one-dimensional analysis. The flame, initiated at the closed end of the long duct, accelerates by the turbulent feedback mechanism, creating a shock wave ahead of it, until the maximum turbulent burning velocity for the mixture is attained. With the confining walls, the mixture is compressed between the flame and the shock plane up to the point where it might autoignite. This can be followed by a deflagration to detonation transition. The maximum shock intensity occurs with the maximum attainable turbulent burning velocity, and this defines the limit for autoignition of the mixture. For more reactive mixtures, autoignition can occur at turbulent burning velocities that are less than the maximum attainable one. Autoignition can be followed by quasi-detonation or fully developed detonation. The stability of ensuing detonations is discussed, along with the conditions that may lead to their extinction. © 2012 by Pleiades Publishing, Ltd.Citation
Bradley, D., Lawes, M., & Mansour, M. (2012). Turbulent deflagrations, autoignitions, and detonations. Combustion, Explosion, and Shock Waves, 48(5), 526–535. doi:10.1134/s0010508212050048Publisher
Pleiades Publishing Ltdae974a485f413a2113503eed53cd6c53
10.1134/S0010508212050048