Numerical analysis of a dual-mode scramjet engine vs a rocket-based combined-cycle engine

Detailed analysis and contrast on the operation features and technical characteristics between a dual-mode scramjet (DMSJ) engine and a rocket-based combined-cycle (RBCC) engine are numerically proposed in this paper in order to deepen the understandings on the RBCC engines. An RBCC engine model is established by integrating a built-in rocket into a mature DMSJ engine. The configurations of the two kinds of engines are kept as identical as possible. They adopt the same inlets, and the combustors and nozzles employing the same lengths and combustion organization methods. Two-dimensional numerical simulations were carried out by Fluent software. As a result, great variations exist between a DMSJ engine and an RBCC engine due to the integration of the built-in rocket, which reflect in many aspects that include inlet design, combustor size, fuel injection and combustion organizations, etc. We should consider an RBCC engine as a distinct propulsion system even relative to a DMSJ engine, and pay sufficient attentions on it. Only take proper use of the built-in rocket, can good performance be achieved in the RBCC engine in a wide Mach range.