New results on the dynamics of annular combustors during ignition and combustion instabilities will be reviewed. Ignition dynamics is considered first by examining experiments carried out in a system comprising a plenum feeding premixed gaseous reactants through multiple swirling injectors and an annular combustor formed by two concentric transparent quartz walls allowing full optical access to the flame. The analysis focuses on the “light-round” process during which the flame spreads from one injector to the next eventually leading to established flames on each injector. The transparent lateral walls allow a full view of the flame propagation from a spark igniter located in the neighborhood of one injector. High speed imaging is used to examine flame displacement and deduce the ignition delay yielding a full light around of the annular combustor. Changes associated to operation with spray flames are then discussed. The second part of this article is concerned with combustion instabilities of annular systems coupled by azimuthal modes. This type of oscillation has received considerable attention in recent years because the underlying coupling is often observed in the advanced premixed combustion architectures used in modern gas turbines. Recent studies have allowed a detailed examination of the dynamics of annular devices comprising multiple swirling injectors. Experiments on annular systems and single sector configurations provide new insight on the coupling process between acoustics and unsteady combustion. Results for self-sustained combustion oscillations coupled by azimuthal modes are presented for operation with gaseous premixed reactants and with spray flames.

将对在点火和燃烧不稳定性期间环形燃烧器动力学的新结果进行回顾。首先，通过检查在一个系统中进行的实验来考虑点火动力学，该系统包括一个通过多个旋流喷射器供入预混合气态反应物的增压室和一个由两个同心透明石英壁形成的环形燃烧器，从而可以完全通过光学通道进入火焰。分析着重于“轻循环”过程，在此过程中，火焰从一个喷射器扩散到另一个喷射器，最终导致每个喷射器上都建立起火焰。透明的侧壁使火焰从位于一个喷油器附近的火花点火器的传播全貌一览无余。高速成像用于检查火焰位移并推导点火延迟，从而在环形燃烧器周围产生完整的光线。然后讨论与喷雾火焰操作有关的变化。本文的第二部分涉及通过方位角模式耦合的环形系统的燃烧不稳定性。由于在现代燃气轮机中使用的先进的预混燃烧结构中经常观察到潜在的耦合，因此这种类型的振荡近年来已受到相当大的关注。最近的研究已经允许详细检查包括多个涡旋喷射器的环形装置的动力学。环形系统和单扇形结构的实验为声学和非稳态燃烧之间的耦合过程提供了新的见识。给出了通过气态预混反应物和喷雾火焰运行时，通过方位角模式耦合的自持燃烧振荡的结果。