RBCC发动机亚燃模态一次火箭引导燃烧的实验

针对使用液体煤油燃料(JP-10)的火箭基组合动力循环(RBCC)发动机在亚燃模态下使用一次火箭作为引导的燃烧组织开展了实验研究.实验在低来流总温条件下,使用小流量一次火箭羽流作为引导火焰可以实现液体煤油的可靠点火和稳定燃烧,并在扩张燃烧室中实现“热力壅塞”,从而完成RBCC发动机亚燃模态的高效燃烧.在目前发动机燃烧室构型下,通过一系列的发动机壁面压力分布曲线和推力增益的比较,研究了凹腔,支板及壁面喷注位置对发动机性能的影响.实验的结果表明:在一次火箭的下游使用支板喷注器可以使得燃料较容易的分布在主流中,并且在一次火焰羽流的引导下可以实现稳定高效的燃烧.支板喷注器的位置对于发动机的性能有很大的影响,在凹腔前壁面横向喷注燃料,有利于RBCC发动机燃烧性能的提升.为了获得较优的发动机亚燃模态性能,需要进一步对燃料的喷注策略开展优化研究. 

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.