An S-type Ascent Trajectory Control Method Based on Scramjet Engine Working Boundary of RBCC

In the development of the Rocket Based Combined-Cycle (RBCC), the scramjet engine is the key problem due to the narrow engine working boundary, which includes limited adjustment capability, and tightly coupled with the RBCC state. It is important to design a reasonable ascent trajectory that exploits the performance of its scramjet engine. Taking account of the working bounds of the RBCC vehicle, an analytical solution method for the ascent trajectory based on the velocity-dynamic pressure standard curve is proposed in this paper, and it uses a preset-height tracking approach to realize the S-type ascent trajectory. This method can be widely applied to design trajectory of RBCC under the performance constraints of scramjet engine, which has strong adaptability and high efficiency of trajectory optimization design.