反向双旋涡流器受限火焰特性的流场分析

分析了反向双旋涡流器受限燃烧火焰特性所对应的流场结构特征.研究发现：反向双旋涡流器流场结构随着受限比变化而发生变化.在受限比小于3.8时，流场上中心回流泡随着受限比增大而变长，与单级旋流涡流器流场上中心回流泡的生长规律相同；但受限比的继续增大，反向双旋涡流器流场上中心回流泡的生长则表现出不同于单级旋流涡流器的规律.单级旋流涡流器流场上中心回流泡会继续生长变长，而反向双旋涡流器流场上中心回流泡会在中间某位置出现分裂，呈现出前后两个不同的回流泡.该研究结果深化了对受限程度影响流动和燃烧的物理机制的认识，同时为反向双旋涡流器的优化设计提供指导.

Flow field analysis for confined flames characteristics of counter dual-stage swirler

Flow characteristics of the confined combustion flames of counter dual-stage swirler were analyzed. Research found that,the flow characteristics of the counter dual-stage swirler changed with the confinement ratio variation. When the confinement ratio was less than 3.8, the center backflow bubble on this flow field grew longer as the confinement ratio increased, with the growth law the same as that of the center backflow bubble on the single-stage swirler flow field. However, as the confinement ratio continued to increase, the growth law of the center backflow bubble was different between the counter dual-stage swirler and the single-stage swirler. The center backflow bubble on the single-stage swirler flow field continued to grow longer, while the center backflow bubble on the counter dual-stage swirler flow field was split into two different backflow bubbles. This result has deepened the understanding of the effect of confinement on flow and combustion, and provided a guidance for the optimal design of the counter dual-stage swirler.