SCCREAM (Simulated Combined-Cycle Rocket Engine Analysis Module): A Conceptual RBCC Engine Design Tool

Rocket-based combined-cycle engines are currently under consideration for use on future, reusable launch vehicles. By combining traditional rocket and airbreathing operating modes into a single engine, multi-mode RBCC engines offer a number of advantages for launch vehicle designers including higher trajectory averaged L^, than pure rockets and higher installed thrust-to-weight ratios than pure airbreathers. This paper presents a new computer tool capable of predicting RBCC engine performance (thrust and 1^) over a wide range of flight conditions and engine operating modes. The tool is called SCCREAM — Simulated Combined-Cycle Rocket Engine Analysis Module. SCCREAM is an object-oriented workstation-level code written in C++. It uses quasi1D flow analysis, component and combustion efficiencies, and an inlet pressure recovery schedule as simplifying assumptions. SCCREAM was created for the conceptual launch vehicle design environment and is capable of quickly generating large tables of engine performance data for use in trajectory optimization. An overview of SCCREAM and the program logic is presented. Results from SCCREAM are favorably compared to historical RBCC engine performance data and to data generated by other engine design tools.