Design and computational investigation of a RBCC propulsion system flowpath for a TSTO concept vehicle

An RBCC (Rocket-Based Combined Cycle) engine flowpath concept, which was used as the first stage propulsion system of a horizontal takeoff TSTO (Two Stage To Orbit) aircraft, was proposed. An integrated inner flowpath (inlet, combustor and nozzle) rapid performance analysis model was established and the flowpath was designed. A variable geometry intake, a combustor which incorporated pylon and cavity for flame holding and a single-expansion-ramp-nozzle were selected to form the flowpath. A validated rapid analysis model was employed to compute the performance of RBCC combustor and comparisons between the 3-D simulations and the engine performance analysis model results on the afterbody flowfield had been performed. An RBCC engine application to a two-stage-to-orbit mission propulsion system was discussed and the propulsion system was analyzed. The performance of the RBCC propulsion system on the flight envelope was evaluated. The results demonstrate that the vehicle with a 280 tonnes launch weight could place a 4 tonnes payload in low earth orbit.