流量非对称性对层流火焰传播速度测量的影响  

EFFECT OF FLOW A SYMMETRY ON DETERMINATION OF LAMINAR FLAME SPEED IN OPPOSED-JET COUNTERFLOW CONFIGURATION

作　　者：许考[1] 张海[1] 樊融[1] 刘青[1] 

机构地区：[1]清华大学热能工程系热能动力工程和热科学教育部重点实验室,北京100084

出　　处：《工程热物理学报》2009年第2期357-359,共3页Journal of Engineering Thermophysics

基　　金：国家自然基金项目(No．50576041);回国人员启动基金(No．041501056)资助项目

摘　　要：对冲火焰被广泛地应用于测量层流火焰传播速度,但实验中常常出现两个喷嘴的流量非对称,造成流场的非对称性。通过数值模拟发现,流量不对称性使得火焰锋面不断移向流量较小的一侧,两侧火焰速度均发生变化,随着流量差增大,流量较大侧得到的层流火焰速度也稍有增加,而流量较小侧的与对称条件下的一致。建议尽量使用流量较小侧作为测量区域。在常规实验的流量偏差内,使用局部拉伸率拟合所得到的层流火焰传播速度是可靠的。Opposed-jet counterflow configuration is commonly used in determining the laminar flame speed of a premixed mixture. However, it is very difficult to keep the flow field in ideally symmetry during the experiments. Numerical simulation on the asymmetry opposed-jet counterflowing methaneair flames was conducted by using CHEMKIN. The results show that though the variation of exit velocity on one nozzle changes the velocity profile and flame location of its own side, but barely affects the velocity profile hydrodynamic zone and flame location on the other side. When asymmetry is presented, the laminar flame speeds obtained of the larger flow rate side slightly increase, while the ones obtained on the smaller flow rate side keep the same as those obtained in the symmetry configuration. It is suggested that the bottom zone is to be used for the measurement. Within the flow field deviation introduced in the experiments, the data of laminar flame speeds, given that. local strain rate is used, are valid.

关 键 词：对冲火焰 非对称 层流火焰传播速度 拉伸率 流场 

分 类 号：TK16[动力工程及工程热物理—热能工程]