湍流扩散火焰的大涡模拟及验证  

Large Eddy Simulation and Verification for Turbulent Diffusion Flame

作　　者：张引弟[1] 周怀春[1] 谢明亮[1] 

机构地区：[1]华中科技大学煤燃烧国家重点实验室,武汉430074

出　　处：《动力工程》2009年第5期451-455,共5页Power Engineering

基　　金：国家自然科学基金资助项目(50721005);国家自然科学基金资助项目(50806023);"111"引智计划基金资助项目(B06019)

摘　　要：对丙烷/空气射流扩散火焰进行了大涡模拟,并就截面流向速度无量纲分布、速度脉动无量纲分布、温度无量纲分布以及NOx生成与Sandia实验室测量数据进行了对比分析,得出大涡模拟方法可以较好地模拟湍流扩散火焰的结论.在此基础上对拟序结构与化学反应的相互影响以及雷诺数对各尺度的影响进行了研究,结果表明:在流场的起始阶段,燃烧对拟序结构的形成有促进作用;在发展阶段,燃烧对大涡拟序结构有削弱作用,却能使小涡的生成增加,从而增强了化学反应;大涡拟序结构的存在改变了各参数的分布;随着雷诺数的增大,各尺度横向脉动均变大,预测到的NOx减小,产生的最大值前移.Large eddy simulation （LES） for propane/air jet diffusion flame was carried out. Compamson and analysis were performed between simulated results and measured data from Sandia laboratory for di- mensionless velocity distribution in the section, dimensionless velocity fluctuation distribution, dimension- less temperature distribution and NOx formation. It is concluded that large-eddy simulation can well simulate turbulent diffusion flame. Then the interaction between coherent structure and chemical reaction as well as the effect of Reynolds number on all scales were studied. Results show that combustion can pro- mote the formation of coherent structures at the initial stage of the flow field, and can weaken the large ed- dy coherent structures but strengthen the small vortices at the developing stage, thus the chemical reaction is strengthened. The existence of large eddy coherent structures changes the distribution of all parameters. With the increase of Reynolds number, all transversal fluctuation scales increase, the predicted formation of NOx reduces and the maximum product moves forward.

关 键 词：湍流燃烧 扩散火焰 大涡模拟 拟序结构 概率密度函数 

分 类 号：TK16[动力工程及工程热物理—热能工程]