CONCEPTUAL DESIGN STUDY ON ROCKET BASED COMBINED CYCLE ENGINE

摘要

In this study, conceptual design of RBCC (Rocket Based Combined Cycle) engine is performed for the hypersonic propulsion system development. For the flight mission, RBCC engine takes off at sea level and accelerates up to Mach 8 at the 30 km altitude. By the flight speed characteristics, operating pattern of the engine is categorized into 3 modes : Ejectorjet (~ Mach 3), Ramjet (Mach 3~6), Scramjet (Mach 6~8) . According to the engine mode characteristics, RBCC engine design and analysis was performed. Each component should be designed to satisfy its critical operating modes. Rocket plume downstream section is designed to satisfy the requirements of ejectorjet mode. The combustor is designed to fit the ramjet mode. Especially in ramjet mode, thermal throat is applied at engine exhaust to obtain the variable nozzle effects. The engine intake is designed to fulfill the requirements of ramjet and scramjet modes. Designed each component is combined and composes an engine. Through performance analysis and evaluation, the designed engine is improved to satisfy every requirement of each operating mode.