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回火被认为是两个完全不同的研究课题。因此，该方案的新颖之处在于研究了这两个主题的相互作用：提出了一项关于大纵横比平板通道中火焰回火的声场(=热声学)的实验研究。为此，将使用扬声器对流量进行声学强制。在第一阶段，将测量声速扰动对回火极限的影响。然后，第二阶段集中于用激光光学方法详细研究这种转变，以便提供对脉动流动所引起的现象的基本理解。最后建立了一个包含声学因素对回闪影响的回闪模型。

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.