Axisymmetric SCRamjet Engine Design and Performance Analysis

Abstract

In the present work, we treat the SCRamjet engine as a system, by coupling different analytical design tools. For the intake portion a Busemann tool was used, the combustion chamber was modeled with a one dimensional reactor, and the nozzle was modeled with the method of characteristics. Performance parameter are discussed while we mainly focus on specific impulse. We used numerical simulations to validate the modeling of the combustion chamber and it turned out that after analytically forcing ignition, the numerical results matched the predictions best. Furthermore, we validated the analytical approach with numerical results and obtained good agreement. According to the analytical tool, for a constant intake pressure ratio of 80 the engine did not ignite at Mach numbers lower than 6 and the specific impulse dropped from 3500 s at Mach 6 to 1200 s and 500 s for Mach 8 and 10, respectively. Due to the small geometry and therefore high friction drag, specific impulse became negative at Mach 11.