The influences of vitiation air generated by ethanol-fueled combustion heating on the performances of kerosene-fueled supersonic combustion were studied numerically when the inflow Mach number at the inlet of combustor is 2.5.Premixed burner-stabilized flame model and ethanol-air reaction mechanism with 61 species and 388 steps were used to simulate the combustion in the heater

helping to obtain the components of high-enthalpy air fluid.The reduced reaction mechanism with 17 species and 30 steps were used to simulate the kerosene-fueled supersonic combustion.The contributions of seven main vitiated species such as H2O

CO2

O

OH

H

CO

H2 to the performance of the supersonic combustion were analyzed.Comparing with the cases of electric-heating on the ground and high altitude at the height of 25km

vitiation air causes the increase of combustion efficiency and internal thrust because of the free-radical's function

decrease of averaged molecular mass and increase of averaged specific heat at constant pressure.