Ignition and Lean Blowout Characteristics of a Reverse-Flow Combustor for an Ultra-Compact Gas Turbine Engine

The flame stability limit and propagation characteristics of a reverse-flow combustor without any flame-stabilized device were experimentally investigated under room temperature and pressure.The results indicate that it is feasible to stabilize the flame in the recirculation zones constructed by the impact jet flow from the primary holes and dilution holes.The flame projected area is mainly distributed in the recirculation zone upstream of the primary holes,whose presence and absence mark the ignition and extinction.During the ignition process,the growth rate and value of the flame projected area first increase and then decrease with the inlet velocity increasing from 9.4 m/s to 42.1 m/s.A rapid reduction followed by a slow reduction of ignition and lean blowout equivalence ratios is achieved by the increased inlet velocity.Then the non-reacting fluid structure in three sections was measured,and detailed velocity profiles were analyzed to improve the understanding of the flame stabilization mechanism.The results are conducive to the design of an ultra-compact combustor.