化学当量比对声场作用下三区火焰动力学行为的影响

Influence of Equivalence Ratio on Dynamical Behavior of Triple Flame Under Acoustic Field

以当量比范围为2.5-∞的甲烷/空气部分预混火焰为研究对象,提取火焰刷特征参数,探究了不同当量比对声场作用下三区火焰动力学行为的影响.结果发现,声场作用下三区火焰长度比稳态火焰明显降低,其辐射强度下降,燃烧稳定性与稳态火焰存在明显差异;化学当量比决定了声场和火焰自身不稳定性对锋面运动的控制程度,在声场作用下三区火焰上游区域主要受到声场作用的影响,而下游区域则为火焰自身动力学和声场作用共同的结果.

Methane/air partially premixed flame with equivalence ratio in the range of 2.5—∞ as research object,influence of equivalence ratio on dynamical behavior of triple flame under the acoustic field is investigated by extracting the flame brush characteristic parameters. Results show that the flame length of triple flame under acoustic decreases obviously compared with that of steady flame. Its radiation intensity decreases,and obvious difference is observed on the combustion stability between the triple flame under acoustic field and steady flame. Equivalence ratio determines the effect of acoustic field and flame instability on flame frontal movement control. The upstream of triple flame under acoustic field is mainly affected by the effect of acoustic field,while the downstream is affected by both flame dynamics and acoustic field.