Experiment of primary rocket-piloting combustion under ramjet-mode condition in RBCC

The experimental studies were performed to investigate primary rocket piloting liquid kerosene (JP-10) combustion in rocket-based combined cycle (RBCC) combustor under typical ramjet-mode condition. Due to the low total temperature of incoming airflow in ramjet mode, the primary rocket with relative low mass flowrate was employed as a piloting flame to achieve reliable ignition and stabilized combustion of liquid kerosene (JP-10) in RBCC combustor. The secondary fuel (JP-10) has been injected into airflow by two strut injectors located behind the primary rocket and an upstream cavity flush-wall injector. The effects of cavity and the location position of strut and wall injection have been investigated.. The strut injectors make the fuel easily be distributed into main airflow, and the results indicate that the injected fuel can accomplish steady and efficient combustion due to the interaction with the rocket plume. The comparisons of the pressure distributions in the combustor under different injection conditions show that the strut injection plays an important role in the combustion of wall injection fuel, and additional wall injection associated with cavity would improve the performance of RBCC combustor. Moreover, the wall injection location and the distance between the wall injection and cavity need to be further considered to obtain optimal engine performance.