Liftoff behaviors and flame structure of dimethyl ether jet flame in CH₄/air vitiated coflow

The objective of this paper is to investigate the flame structure and liftoff behaviors of a dimethyl ether central jet in CH4/air vitiated coflow in a coflow burner. The liftoff behaviors of dimethyl ether jet flames in the air flow were studied firstly. The flame stability of the burner was analyzed by measuring the flow field temperature with thermocouples. By changing the coflow rate and CH4 equivalence ratio, the liftoff behaviors of dimethyl ether jet flames under different vitiated coflow environments were discussed. The jet flame structure was also analyzed qualitatively by high-speed photography.