基于DMSJ发动机流道的RBCC发动机设计

RBCC engine design based on the flow passge of DMSJ engine

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。

The flow passage and combustion organization design of a DMSJ engine is carried out firstly.The specific impulse of the DSMJ engine is 1 029.6 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 Moo 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.