中文摘要：

本文将气流扬声器作为激励源,研究旋流预混火焰在入口速度扰动下的火焰动力学响应特性,并通过测量不同扰动频率下的火焰放热率变化规律得到火焰传递函数。实验结果表明,随扰动频率的变化火焰结构会发生显著变化,火焰传递函数幅值随扰动频率的变化呈现单峰特性。当量比较小时,火焰传递函数的幅值可能大于1,火焰对速度扰动较敏感。利用n-τ模型对实验测量的火焰传递函数进行拟合,结果显示随当量比的增加,特征频率增加,且在特征频率两侧延迟时间不同。

英文摘要：

This study uses an electropneumatic loudspeaker to produce acoustic wave and investigates the premixed swirling flame dynamic response characteristics under inlet velocity perturbations.Flame transfer function（FTF） is obtained via measurement of the flame heat release rates under different frequency perturbations.The results show that the flame structure undergoes obvious variations at different frequencies.The amplitude of FTF presents a single peak distribution in the frequency domain.FTF amplitude can be larger than one at lean flame conditions,and the flame is sensitive to velocity perturbations.The measured FTF results are fitted according to the n-τ model.The results indicate that the characteristic frequency increases with the equivalence ratio.In the smaller and larger frequency ranges on the two sides of this frequency,the time delay can be different.