火焰拉伸对甲烷/空气和丙烷/空气层流燃烧速度的影响  

Strain rate effects on the integral burning velocity of laminar premixed CH4/air and C3H8/air flames

作　　者：倪娟娟[1] 陈永辰[1] 王宏光[1] 

机构地区：[1]上海理工大学叶轮机械与流体工程研究所,上海200093

出　　处：《能源研究与信息》2009年第1期55-61,共7页Energy Research and Information

基　　金：上海市重点学科建设资助项目(J50501)

摘　　要：通过拓展层流火焰消耗速度的概念,将其定义与反应进程变量(progress variable)的定义相结合,给出了一个积分层流燃烧速度的广义定义。在准一维稳态系统中,分析了积分层流燃烧速度,以及其与未燃气体的位移速度和已燃气体的位移速度之间的关系。对甲烷—空气和丙烷—空气拉伸层流预混火焰在常温常压下进行了数值计算,研究了在不同当量比下,火焰拉伸对层流燃烧速度的影响,并得出了马克斯坦长度。对基于通过火焰前锋放热率的积分层流燃烧速度和基于燃料消耗率的积分层流燃烧速度进行了比较。结论表明低拉伸火焰的马克斯坦数与渐进分析一致,也与球形火焰获得的实验数据吻合。The definition of the consumption speed for a laminar premixed flame is extended into an integral laminar burning velocity associated with a particular definition of the reaction progress variable. An analysis of the integral laminar burning velocity, particularly its relationship to the displacement speed on the unburned and burned sides, is performed for a quasi one-dimensional, steady system. Numerical calculations are also made in counterflow geometry for methane-air and propane-air premixed flames at atmospheric pressure and ambient temperature for a wide range of equivalence ratios to examine the strain rate effects. The integral laminar burning velocity based on integration of the heat release rate across the flame front is compared with that based on integration of the fuel consumption rate. Results show that values of the derived Markstein length from flames of low strain rates are consistent with asymptotic analysis. They also agree reasonably well with experimental data obtained from the outwardly propagating spherical flames.

关 键 词：层流燃烧速度 拉伸 马克斯坦数 预混火焰 放热率 

分 类 号：TK16[动力工程及工程热物理—热能工程]