Ignition characteristics in a thin strut-equipped dual mode combustor fueled with liquid kerosene

Ignition characteristics in a strut-equipped dual mode combustor fueled with liquid kerosene were observed and discussed in this paper. A series of experiments and numerical simulations were carried out in the combustor both at the high-speed mode (Ma = 2.8) and at the low-speed mode (Ma = 2.0). Combustion establishment process and flame characteristics were captured and analyzed with the method of high-speed photography. Results indicated that two flammable regions, namely the recirculation region and the shear layer, generated in the combustor with the assistance of strut. Then, the optimization of ignitor parameters, including installation location of ignitor and ignitor power, had been conducted to achieve a stable flame successfully in these two flammable regions. During the flame establishment process, the ignition delay characteristics and the fluctuation energy of flame, adopted as the main parameters to estimate the ignition characteristics, were analyzed and discussed in different experimental conditions, which were mainly affected by operating Mach number, equivalence ratio of fuel, and mass flow of oxygen. The analysis results of these impacts on ignition process in this paper was beneficial to the optimization of ignition scheme in dual mode combustor for future investigations. •Two flammable regions were established at trailing edge of strut.•Ignition parameters were optimized to achieve successful ignition.•Three influencing factors on ignition characteristics were discussed.•The flame establishment process and its characteristics was revealed.