微小Swiss-roll燃烧器的数值模拟  

Numerical Simulation of Micro Swiss-Roll Combustor

作　　者：李军伟[1] 钟北京[1] 王建华[1] 

机构地区：[1]清华大学航天航空学院,北京100084

出　　处：《燃烧科学与技术》2008年第6期533-539,共7页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(50376027)

摘　　要：为了解微小Swiss-roll燃烧室的工作特点,对二维Swiss-roll燃烧器进行数值模拟,采用了CH4/空气的多步反应机理,考虑了燃气对室壁的辐射,研究当量比和入口气流速度对燃烧特性和火焰稳定性的影响.研究结果表明,Swiss-roll燃烧器能够在大的当量比范围内稳定工作.但上下极限并不对称,富燃时的极限比较小,比化学当量比略小,而富氧的极限比较大.对于相同的当量比,流速较小时,甲烷/空气火焰停留在燃烧器中心区的入口,甲烷全部参加反应;随着气体流速的增加,在燃烧器的中心形成回流区,扩大了燃烧器的富氧可燃极限,有助于火焰稳定,但是甲烷的转化率在减小.To understand the working features of the micro Swiss-roll combustor, numerical simulations for a 2D Swiss-roll combustor were carried out, with CH4/air multi-step reaction mechanism and radiation from gas to channel wall taken into consideration. Effects of equivalence ratio and flow velocity on combustion characteristics and flame stability were studied. The results show that the Swiss-roll eombustor can work with in a wide range of equivalence ratios. But the fuel-rich limit is not symmetrical to the fuel-lean limit. The former is just less than 1, while the later is much larger than 1. For the same equivalence ratio, if velocity is small, flame is stabilized at the entrance of the center region with complete combustion of methane. With the increase of flow velocity, there appears a recirculating zone in the center region, hence increasing the fuel-lean limit and enhancing flame stabilization. But the recirculating zone can decrease the conversion ratio of methane.

关 键 词：微小燃烧室 预混燃烧 数值模拟 甲烷 燃烧特性 

分 类 号：TK16[动力工程及工程热物理—热能工程]