合成气预混层流本生灯火焰顶端开口机理研究  

Tip Opening of Laminar Premixed Syngas/Air Bunsen Flames

作　　者：王金华[1] 俞森彬 卫之龙[1] 金武[1] 谢永亮[1] 黄佐华[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049

出　　处：《工程热物理学报》2015年第8期1841-1845,共5页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No.51376004);陕西省自然科学基金(No.2014JQ7267);天津大学内燃机燃烧学国家重点实验室开放课题基金(No.K2014-4);教育部留学回国人员科研启动基金

摘　　要：利用OH-PLIF火焰结构激光诊断技术获得了不同当量比下CO:H_2为1:4的合成气预混层流本生灯火焰OH基分布。结合STAR-CD模拟结果,分析了拉伸率和优先扩散随当量比的变化规律,以及变当量比条件下拉伸率和优先扩散的相互作用机理。结果表明,本生灯火焰顶端是强烈负拉伸,由火焰弯曲引起的强负拉伸和流动引起的微弱正拉伸共同作用。在稀燃条件下,随当量比的减小,顶端负拉伸作用增强,加剧局部优先扩散作用,引起未燃混合气中的燃料比例下降,削弱顶端局部燃烧强度,导致顶端开口现象。Effects of stretch and preferential diffusion on tip opening of laminar premixed syngas/air Bunsen flames at various equivalence ratios were investigated with experiments and numerical simulation.Results show that the flame tip of laminar premixed Bunsen flame is strongly negative stretched with a strong negative stretch due to flame curvature combined with slight positive stretch due to flow strain.For lean combustion,the negative stretch increases with the decrease of equivalence ratio,which promotes the local preferential diffusion,leading to the reduction of fuel fraction in the reactants.This results in the even leaner mixtures in the flame tip and supperss the local combustion intensity as well as the occurrane of flame tip opening.

关 键 词：顶端开口 拉伸率 OH-PLIF 优先扩散 合成气 

分 类 号：TK123[动力工程及工程热物理—工程热物理]