Hypersonic Transport Propulsion System Research (HYPR) Project was started in 1900 to develop technologies for the propulsion system of a Mach 5 Hypersonic Civil Transport, which could be environmentally acceptable and economically viable. The engine being studied is the methane fueled combined cycle engine composed of a turbo-accelerator for low speed range and a ramjet engine for high speed range. what is called a turbo/ramjet engine. The turbo-accelerator is required to meet the low noise regulations at take-off and achieve high specific thrust at high speed flight like the second generation SST (Supersonic Transport) engine. The single bypass turbofan engine (SBE) with variable cycle concept was selected as the turbo-accelerator engine to meet the above requirements in one engine. The engine was conceived to have variable geometry in compressor stator, low pressure turbine stator, fan bypass flow nozzle aren and exhaust nozzle area for low jet velocity at take-off and high jet velocity at altitude high speed and be equipped with a mixer ejector in the exhaust nozzle for further noise reduction.
This paper describes the cycle study and conceptual design of the demonstrator of a turbo-accelerator engine being planned to be tested in 1903.
