Rocket Based Combined Cycle Propulsion System Research Articles

Research and development on inlets for rocket based combined cycle engines

Rocket based combined cycle (RBCC) engine is regarded as one of the most efficient propulsion systems for reusable space transportation vehicles and hypersonic cruise vehicles. It can perform excellently over a very broad range of Mach numbers and flight altitudes through multi-mode operations by effectively integrating high thrust-to-weight ratio of the rocket engine and high specific impulse of the airbreathing engine. The RBCC inlet, commonly operating in an extremely wide flight speed range covering static, subsonic, transonic, supersonic, and hypersonic, plays a vital role in the RBCC propulsion system and flight vehicles. This paper presents a comprehensive and systematical review of the research progress on the inlets for RBCC engines in different countries and different historical periods. A number of key technical and scientific issues specially concerning RBCC inlets are sorted out, including the wide range RBCC inlet design and optimization, inlet/embedded rocket/combustor matching and control, dynamic operation, etc. Several typical RBCC inlet applications and the corresponding research are discussed, including the Strutjet inlet, A5 inlet, GTX inlet, and the Astrox's inlet in the U.S., the RBCC inlet in JAXA, and a sidewall compression RBCC inlet in China. Finally, experience gained and some recommendations are summarized for future research of the RBCC inlet.

An analysis tool of the rocket-based combined cycle engine and its application in the two-stage-to-orbit mission

The rocket-based combined cycle (RBCC) engine is believed to be an ideal propulsion system for the space round trip mission in the future. The mission planning process is limited because there is no available performance data on the RBCC engine. This paper proposed a thermodynamic analysis tool of the RBCC engine. Working over a wide speed range, this tool divides the engine’s working process into four modes, namely the ejector, the ramjet, the scramjet and the pure rocket modes. The results are validated by data in the previously published literatures. Based on this tool, the equal-dynamic pressure trajectory analysis is implemented for the first stage of a two-stage-to-orbit vehicle equipped with an RBCC propulsion system. The influences of the launch weight and the engine size of the vehicle on the acceleration performance are studied. The dynamic pressure of the designed trajectory is also in the scope of this work. The results show that a lighter launch weight, a larger engine size and a larger designed dynamic pressure are positive for the fast acceleration process with lower fuel consumption. In addition, a long distance transportation mission requires different design conditions with that in the fast acceleration mission.