To investigate the influence and kinetic mechanism of plasma on the ignition delay of the ethylene/air mixture under rich burn condition

the sensitivity analysis and rate of production method were adopted to analyze the mechanism of ethylene/air ignition delay with different concentrations of H and O atoms under equivalence ratios of 1.0

1.5 and 2.0.The results show that

under the conditions of 0.1 MPa and 1 000 K with constant equivalence ratio

the higher the concentration of H atom is ad

ded

the shorter the ignition delay of ethylene/air will be

and the maximum ignition delay reduces by 99.5%.O atoms can also shorten the ignition delay of ethylene/air

the minimum ignition delay is only 1/3compared with adding the same concentration of H atoms.Different with the condition of no plasma

under the conditions of different equivalence ratios but in the same concentration of active particles

the ethylene/air ignition delay decreases first and then increases with the elevation of equivalence ratio as the concentration of active particles increases.Compared with the minimum ignition delay of 1.5×10

-4

s

after adding 2.0%H atom

the increase of equivalence ratio will cause the ignition delay to increase by 7.3%

18.4%

respectively.When adding 2.0%O atom

compared with the minimum ignition delay of 4.8×10

-5

s

the ignition ratio will increase by 14.0%

32.9%respectively with elevation of equivalence ratio.The H atom mainly shortens the ignition delay by directly affecting the reaction H+O

2

=O+OH

H+O

2

（+M）=HO

2

（+M）;The O atom accelerates the formation of H atoms by affecting the reaction C

2

H

4

+O=CH

2

CHO+H

and promotes reaction rates of the chain transfer reaction H+O

2

=O+OH

HO

2

+H=2OH to shorten the ethylene/air ignition delay.