基于DMSJ发动机流道的RBCC发动机设计

首先完成了一种典型DMSJ发动机流道型面和燃烧组织设计,该发动机在M_∞=4.0和6.0时的比冲分别为1 029.6 s和899.9 s。以此DMSJ发动机流道为基础,在隔离段一侧布置火箭发动机,形成RBCC发动机流道。数值模拟研究表明,低马赫数时,火箭台阶及下游流道型面变化对发动机性能影响有限;保持DMSJ发动机燃料喷注方案不变,RBCC发动机在M_∞=4.0时,冲压模态比冲可达到1 052.8 s。高马赫数时,由于燃烧组织位置靠前,必须对DMSJ发动机原有的燃料喷注方案进行调整,才能确保RBCC发动机达到与前者相当的比冲水平,经过调整本文RBCC发动机M_∞=6.0时冲压比冲达到了887.8 s。因此,基于目前较成熟的DMSJ发动机进行高马赫数RBCC发动机设计,是一条快速可行的技术途径。

RBCC engine design based on the flow passge of DMSJ engine

The flow passage and combustion organization design of a DMSJ engine is carried out firstly.The specific impulse of the DSMJ engine is 1029.6 s when M∞=4.0,whereas it is 899.9 s when M∞=6.0.A RBCC engine flow passage is obtained by pla-cing a rocket engine on the isolation sidewall of the DMSJ engine.Investigation shows that the rocket shoulder and downstream flow passage scheme variation have limited influence on engine specific impulse when M∞ is lower.The RBCC engine specific impulse is 1052.8s when M∞=4.0,with the same fuel injection mode as the DMSJ engine.In order to gain a comparable specific impulse to that of DMSJ engine when M∞ is higher,the fuel injection mode of the RBCC engine should be different from the DMSJ engine.The com-bustion organization positions of two engines are both in the upstream flow passage when M∞ is elevated.The specific impulse of RB-CC engine is 887.8 s when M∞=6.0,with the regulating of the fuel injection mode.Therefore,it is facile and feasible to design a RBCC engine based on traditional mature DMSJ engine.