Study of RBCC Ejector Jet Mode

We study the thrust performance of the ejector jet mode of RBCC by numerical analysis. We simulate JAXA engine operating condition in the ejector jet mode with Mach 0, 0.3, 0.6 and 2 conditions. Its performance is estimated. We also examined transportation ability of a space plane propelled with RBCC and compared the ability with that rocket engine. The space plane with RBCC showed superior performance to the rocket plane. Numerical simulation was conducted for the JAXA RBCC engine under the Mach numbers of 0, 0.3, 0.6 and 2. At airflow Mach numbers of 0, 0.3, and 0.6, thrust could be successfully generated. At a Mach number 2.0, performance was improved by increasing the total pressure of the rocket engine. Calculations for an airflow Mach number of 2 were performed under atmospheric pressure of 1 atm and an atmospheric temperature of 293 K. In contrast, in an actual flight environment at Mach number 2, the environmental pressure is approximately 0.1 atm and the atmospheric temperature is approximately 216 K. A higher specific impulse can be obtained by performing simulations based on actual flight environment conditions, not only for an airflow Mach number of 2 but also for an airflow Mach number of 0.6.