Flame oscillation characteristics in a kerosene fueled dual mode combustor equipped with thin strut flameholder

摘要

Flame oscillation 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 in lower inflow enthalpy condition (Ma = 2.0) and in higher inflow enthalpy condition (Ma = 2.8). The methods of high-speed photography and pressure measurement were used to record the basic data, and based on the basic data, the variation of flame area and the distribution law of wall pressure in different experimental conditions were analyzed to get the flame oscillation characteristics. Results indicated that the phenomenon of flame oscillation was caused by the variation of pilot flame strength and the adverse pressure gradient near the combustion region. Flame oscillation was distinguished into different status according to oscillation frequency and oscillation amplitude, and both the mass flow of oxygen and equivalence ratio could make a deep influence on the flame oscillation status. Flame oscillation characteristics were also closely related to the flowing state, and the difference of flame propagation process in supersonic and subsonic flowing conditions resulted in the distinction of flame oscillation characteristics. With the investigations in this paper, a depth understanding on flame oscillation in the dual mode combustor is achieved.