Dynamical Instabilities in Laminar Premixed Flames

对层流预混火焰的动力不稳定性进行了实验研究。结果将与理论燃烧科学和非线性动力学的最新预测进行比较。大部分的研究都是在多孔塞式燃烧器上进行的低压烃类空气火焰。先前对低压燃烧器稳定碳氢化合物火焰的实验研究已经确定了四种非稳态传播模式：火焰锋面垂直于燃烧器的轴向传播模式；火焰锋面在燃烧器上周期性改变其空间范围的径向模式；一种螺旋模式，其中火焰前缘呈非平面形状，如鞍形。即使是最复杂的火焰锋面运动也只能用几种模式来描述。观测结果与火焰在通道中自由传播的预测相似。本实验研究是为了确定这些模式的时空特征作为外部参数的函数。此外，还将从非线性动力学和混沌系统理论的角度对燃烧现象进行研究。

An experimental study of dynamical instabilities in laminar premixed flames is conducted. The results are to be compared with recent predictions of theoretical combustion science and nonlinear dynamics. Most of the research is to be conducted on low-pressure, hydrocarbon-air flames on a porous plug burner. Prior experimental studies of low-pressure, burner-stabilized hydrocarbon flames have identified four nonsteady modes of propagation: an axial made in which the flame front moves perpendicular to the burner; a radial mode in which the flame front periodically changes its spatial extent on the burner; a spiral mode in which the flame front assumes a nonplanar shape, such as a saddle. Even the most complicated motion of the flame front is described by only a few modes. The observations are similar to predictions for flames freely propagating in channels. This experimental study is to determine the spatial and temporal characteristics of these modes as a function of the external parameters. In addition, several studies are to be conducted which examine combustion phenomena from the perspective of nonlinear dynamics and the theory of chaotic systems.