The experimental data on lean blow out fuel/air ratio of a single-dome swirl cup combustor was obtained at 388 K inlet temperatures and atmospheric pressure with different inlet air velocities.Using flamelet combustion model with detailed chemical mechanism

numerical simulations were performed to get the details of local hot flow field.Results show that

near the lean blow out point

with the decline of fuel/air ratio

the vortex core is separated from high temperature zone

and the temperature in recirculation zone drops

and the ignition point moves backward

so the ignition distance increases.With the increase of inlet air velocity and decrease of the fuel mass flow rate

the mass flow rate of the recirculation and the temperature difference between two sides of the vortex core become greater

but the ignition point stays further back

showing that the flame has greater tolerance with their difference.