Influence of Acoustic Forcing on the Transition from Flame Stabilization to Flashback at Channel Exits

在过去，燃烧不稳定性和火焰闪回被认为是两个完全不同的研究课题。因此，该提议的新颖之处在于研究这两个主题的相互作用：提出了一项高纵横比平坦通道中火焰闪回的声场（=热声）实验研究。为此目的，将使用扬声器施加流的声强迫。在第一阶段，将测量声速扰动对闪回极限的影响。第二阶段的重点是用激光光学方法对过渡进行详细的研究，以便对脉动流产生的现象提供基本的了解。最后建立了一个包含声学对闪回影响的闪回模型。

In the past, combustion instabilities and flame flashback have been considered to be two entirely different research subjects. For this reason, the novel aspect of the proposal lies in the investigation of the interaction of both topics: An experimental study of acoustic fields (=thermoacoutics) on flame flashback in flat channels of high aspect rations is proposed. For this purpose acoustic forcing of the flow with loudspeakers will be applied. In the first phase, the influence of the acoustic velocity perturbations on the flashback limits will be measured. The second phase is then focussed on the detailed investigation of the transition with laser optical methods in order to provide the basic understanding of the phenomena resulting from pulsating flow. Finally a flashback model will be developed, which incorporates the influence of the acoustics on flashback.