平面突扩管道中的湍流流动及预混燃烧计算

 应用随机涡法(Random Vortex Method)对平面后台阶突扩管道中的湍流流动及预混燃烧过程进行了数值计算。与平均流场所显示的气流结构不同,瞬时流场表现出大尺度的多涡结构。由于这些大尺度旋涡之间的相互作用,回流区长度在平均值附近发生拟周期性变化。预混燃烧计算结果表明,大尺度旋涡对火焰面在流场中的分布有重要影响。

CALCUATION OF TURBULENT FLOW AND PREMIXED COMBUSTION IN A 2-D SUDDEN EXPANSION CHANNEL

The random vortex method is used to model turbulent flow and premixed combustion in a 2-D sudden expansion channel. The averaged and instantaneous velocity fields are presented. In contrast with averaged velocity field, more than one large-scale vortexes appear in instantaneous velocity field. Owing to the interaction between these large-scale vortexes, the length of recirculating-flow region changes periodically about the averaged value. The calculation of premixed combustion shows that, these large-scale vortex structures play an important role in the distribution of flame front in the flow field.