Survey on key techniques of rocket-based combined-cycle engine in ejector mode

A rocket-based combined-cycle engine prototype demonstrating comprehensive component compatibility and effective mode transition

Numerical analysis of flow features and operation characteristics of a rocket-based combined-cycle inlet in ejector mode

Research progress on ejector mode of rocket-based combined-cycle engines

Rocket-based combined-cycle (RBCC) engines are known as the most promising type of engine with the potential to realize ‘single stage to orbit’ (SSTO). This will dramatically reduce the cost of space round trips and improve the physical experience of astronauts. However, sixty years after this concept was first proposed, no RBCC engine has completed a real flight. The challenges in RBCC development include ejector, scramjet, mode transition, and thermal protection technologies. However, great progress has been made in recent years, suggesting a bright future for these engines. In this paper, we review worldwide progress in the overall layout of RBCC engines. The working process of RBCC engines is introduced to show their distinctiveness among traditional engines. RBCC engines are classified as rectangular section or axisymmetric configuration engines and the development of both types in different countries is reviewed. The engine-airframe integration design and mission planning of RBCC powered aircraft systems are analyzed separately. Even though RBCC powered aircraft and their missions remain conceptual, the design and planning processes are important for RBCC development and space round trips in the future. RBCC study is a typical multi-disciplinary design process. Research addressing the problems encountered by RBCC studies will promote the development of a range of disciplines relevant to aerospace science.

The overall layout of rocket-based combined-cycle engines: a review

Experimental tests are conducted to evaluate two rocket exhaust configurations within an Rocket-Based Combined Cycle engine model. Each configuration uses a single rocket chamber but expands the rocket exhaust to a different geometry. One configuration uses two traditional circular rocket nozzles whereas the other uses two annular exhaust geometries based on the Exchange Inlet design. Wall pressure data are collected along the length of each configuration to evaluate the air entrainment. The annular configuration is shown to increase the entrainment ratio by as much as 28% over the traditional circular rocket design. The annular configuration is also shown to choke the incoming airflow at a lower rocket chamber pressure more uniformly across the engine cross section. Total pressure measurements are also obtained at the engine exit plane, which show that the annular configuration yields an average Mach number 57% higher than the circular configuration under conditions close to those for maximum air entrain...

S. Ueda

Papers

Experimental Investigation of an Alternative Rocket Configuration for Rocket-Based Combined Cycle Engines