A SIMPLE ROCKET BASED COMBINED CYCLE ENGINE for Advanced Launch Vehicles

摘要

A simple combined cycle engine incorporating features of both solid-fuel ramjets, and hybrid propellant rockets was examined for use in a single-stage launch vehicle, and as a booster in a two-stage vehicle. Paraffin was chosen as the solid fuel due to its high regression rate and relatively high performance. A hypothetical vehicle was examined: a lifting launcher with a hybrid propellant rocket mode and solid-fuel ram/scram jet mode. The vehicle had a takeoff mass of 319,500 kg. Approximate component masses were calculated to run 2D trajectory simulations of the flight and determine the engine performance and effective payload masses. Neither system was heavily optimized, but the SSTO version nonetheless has a payload fraction to LEO of roughly 3.38%, which is substantially greater than the 2% payload the all-rocket Venturestar™ vehicle would have had, and the two stage version substantially out-performs the Falcon-9 with booster reuse.