Flow Characteristics and Ignition Performance Analysis of an Evaporating Cavity Trapped Vortex Pilot Flame-Holder

In order to further broaden the ignition and blowout boundary of the cavity trapped vortex flame-holder at low temperature and high speed flow conditions，a novel preheated and premixed fuel supply method us⁃ ing core hot gas，is proposed for the evaporating cavity trapped vortex pilot flame-holder. The flow characteris⁃ tics，fuel distribution characteristics and ignition performance under wide range flow conditions of evaporating cavity trapped vortex pilot flame-holder are obtained. The results show that the vortex structure formed inside the cavity and mixing chamber of the evaporating cavity trapped vortex pilot flame-holder provide favourable condi⁃ tions for ignition and combustion at low temperature and high speed. The fuel spray distribution in the vortex zone of the cavity is evenly distributed in the flow direction，and decreases from the richest of the symmetrical meridi⁃ an surface of the flame-holder to the poorest of the middle surfaces of the adjacent flame-holder along the circum⁃ ferential direction. At the same flow temperature，the lean ignition and blowout equivalent ratio of the evaporating cavity trapped vortex pilot flame-holder increases with the increase of the inlet speed. Under low temperature （600K），high speed（100~200m/s）flow conditions，compared with evaporating Z-shaped flame-holder and tra⁃ ditional film evaporation flame-holder，evaporating cavity trapped vortex pilot flame-holder can decrease the ig⁃ nition equivalent ratio by 5.5% and 30%，respectively. Blowout equivalent ratio can be decreased by 37.4% and 48.8%，respectively. © 2023 Journal of Propulsion Technology. All rights reserved.