Oleg Aleksandrov, a designer from Orekhovo-Zuyevo, proposed an unusual rocket engine scheme that combines a rocket combustion chamber and a hypersonic ramjet engine. The design is based on an annular combustion chamber with a central body.
A nozzle is located around it, forming an additional channel for the ramjet engine. Inside, combustion of incoming air is provided for subsonic modes, and the outer surface of the nozzle forms the chamber of the hypersonic ramjet engine.
That is, one propulsion system is designed for several operating principles at once. The rocket part does not depend on atmospheric air, and the ramjet circuits use the incoming flow and are connected as speed changes.
A separate solution concerns the fuel tank. Its tail section is used as the central body of the annular chamber, and the units located inside ensure the engine's operation and fuel component supply.
To regulate the airflow, the design includes a movable ring with a conical profile. It changes the area of the air intake depending on the operating mode. For the hypersonic circuit, the developer also provided several belts of nozzles that can be activated depending on the speed range.
The power scheme itself can be adapted for various execution options, including the manufacture of individual elements from metal, composite, or by 3D printing.