Different stages of flame acceleration from slow burning to Chapman-Jouguet deflagration

作     者：Damir M. Valiev Vitaly Bychkov V’yacheslav Akkerman Lars-Erik Eriksson 

作者机构：Department of Physics Umeå University S-901 87 Umeå Sweden Department of Materials Science and Engineering Royal Institute of Technology SE-10044 Stockholm Sweden Department of Mechanical and Aerospace Engineering Princeton University D323-A Engineering Quad. Princeton New Jersey 08544-5263 USA Department of Applied Mechanics Chalmers University of Technology 412 96 Göteborg Sweden 

出 版 物：《Physical Review E》 (物理学评论E辑：统计、非线性和软体物理学)

年 卷 期：2009年第80卷第3期

页      面：036317-036317页

核心收录：

学科分类：07[理学] 070203[理学-原子与分子物理] 0702[理学-物理学] 

基　　金：Swedish Research Council (VR) Kempe Foundation High Performance Computer Center North (HPC2N), Umea, Sweden [007-07-25] 

主　　题：Acceleration 

摘      要：Numerical simulations of spontaneous flame acceleration are performed within the problem of flame transition to detonation in two-dimensional channels. The acceleration is studied in the extremely wide range of flame front velocity changing by 3 orders of magnitude during the process. Flame accelerates from realistically small initial velocity (with Mach number about 10−3) to supersonic speed in the reference frame of the tube walls. It is shown that flame acceleration undergoes three distinctive stages: (1) initial exponential acceleration in the quasi-isobaric regime, (2) almost linear increase in the flame speed to supersonic values, and (3) saturation to a stationary high-speed deflagration velocity. The saturation velocity of deflagration may be correlated with the Chapman-Jouguet deflagration speed. The acceleration develops according to the Shelkin mechanism. Results on the exponential flame acceleration agree well with previous theoretical and numerical studies. The saturation velocity is in line with previous experimental results. Transition of flame acceleration regime from the exponential to the linear one, and then to the constant velocity, happens because of gas compression both ahead and behind the flame front.