中文摘要：

一个有限反应率模型表现为大旋涡模拟(LES ) 的闭合数字地学习打漩的一口开的 premixed 甲烷 / 空气火焰。结果的模型被与报导数据作比较第一验证然后采用了调查打漩的效果流动地，火焰特征和打漩的火焰的燃烧不稳定性上的紧张。三不同打漩数字被考虑。LES 结果证明作为打漩，紧张增加，旋涡乘火车并且微混合被提高，在火焰前面导致更多的瘦相等的比率；因而，更高的打漩数字原因降低火焰温度和更慢的公司氧化；因为模仿的所有打漩数字，火焰前面完全从再通行地区被定位并且在环形的打漩蒸气的内部表面抛锚了；打漩数字在打漩上有关键效果向光线、正切的尺寸然后显著地的火焰扩展影响 streamwise 火焰长度，它是燃烧不稳定性上的一个大影响因素；在 streamwise 的火焰上的导致旋涡的骚乱在燃烧不稳定性起一个关键作用。

英文摘要：

A finite reaction rate model is presented as a closure of large eddy simulation （LES） to numerically study an open premixed methane/air swirling flame. The resultant model is firstly validated by comparing with reported data and then employed to investigate the effect of swirling intensity on flow field, flame characteristics and combustion instability of the swirling flame. Three differ- ent swirl numbers are considered. The LES results show that as swirling intensity increases, the vortex entrainment and micro-mixing are enhanced, leading to more lean equivalent ratios at flame front; consequently, higher swirling number causes lower flame temperatures and slower CO oxidization; for all simulated swirl numbers, flame fronts are completely located out of the recirculation zones and anchored at the inner surface of the annular swirling steams; swirl number has a crucial effect on swirling flame extension toward radial and tangential dimensions and then significantly affects streamwise flame length, which is a great influencing factor on combustion instability; vortex-induced disturbance on flame in streamwise plays a critical role in combustion instability.