Experimental investigation on the flame propagation pattern of a staged partially premixed annular combustor

摘要

The transient ignition process of a staged partially premixed low-emission annular combustor was investigatedexperimentally in this paper. This study focused on the mechanism of injector-to-injectorflame propagation. For various overall equivalence ratios and bulk velocities, a side visualization of thespreading flame captured by 10 kHz high-speed imaging technology during the light-round process illustratedthat flame propagation from injector to injector presents three typical modes: spanwise-upstream,archlike-entrainment, and spanwise-entrainment, instead of following a purely azimuthal direction. Thedetailed processes of flame propagation with the various modes were analysed based on the flow fieldand spray patterns. Three schematic diagrams for the injector-to-injector flame propagation modes wereestablished. The injector-to-injector flame propagation mode is dependent on the bulk velocity and equivalenceratio, which have a critical impact on the flow field and spray pattern as well as the subsequentflame morphology of the dome.