管内层流火焰传播中的Lewis数影响  

Lewis number's effect on flame propagation in open-end pipes

作　　者：丁敏[1] 陈义良[1] 赵平辉[1] 

机构地区：[1]中国科学技术大学热科学与能源工程系,安徽合肥230027

出　　处：《中国科学技术大学学报》2008年第4期400-404,共5页JUSTC

基　　金：自然科学基金(10372099;50376060)资助

摘　　要：采用17组分、53基元反应的详细化学反应机理,通过数值模拟开口微细圆管中的层流传播火焰,分析Lewis数等于1的假定对计算结果的影响,尤其是对火焰传播速度和熄火的影响.结果表明,Lewis数等于1的假定,忽略了自由基的强扩散能力,导致火焰面附近自由基浓度增大、火焰面形状失真、火焰传播速度减小以及壁面熄火效应减弱等.因此,在采用多步化学反应机理的层流火焰模拟中,必须采用真实的Lewis数.The laminar propagation flame was numerically simulated in open-end micro pipes using 17 species and 53 elemental reactions. The effects on the calculated results such as flame propagation speed and flame quenching were analyzed based on the assumption of the Lewis number equaling one. The results show that the assumption of the Lewis number equaling one neglects the intense diffuse capability of the radicals and results in the increase of the concentration of the radicals near the flamelet, the distortion of the flamelet, the decrease of flame propagation speed and weakening of the wall boundary effect on flame quenching. So the real Lewis number should be used when the laminar flame is modeled using the detailed chemical reaction mechanism.

关 键 词：微细圆管 二维流场 壁面散热 Lewis数 

分 类 号：TK473.2[动力工程及工程热物理—动力机械及工程]