Design and analysis of 10 kn LOX/RP-1 rocket engine with extendable diffuser

This study presents significant insights into the behavior of fixed rocket nozzles under varying pressure conditions, offering valuable information about the design, performance, and expansion phases of liquid rocket engines. The potential for enhancing thrust performance through full expansion at sea level has been observed. By shortening the length of the fixed nozzle rocket motor, full expansion at sea level was achieved, followed by achieving full expansion at 10 km altitude using a nozzle extension. A rocket motor with an extendable nozzle structure produces 9867 N of thrust at sea level, while a rocket motor with a fixed nozzle structure produces 9002 N of thrust. These results highlight that the extendable nozzle structure is more closely aligned with the targeted thrust value and effectively embodies the design intent. Furthermore, the design of a 10 kN thrust capacity liquid bipropellant rocket motor, including the extension mechanism, has been developed, with manufacturing planned using CNC machining techniques and integration achieved through welding methods. The thrust chamber design has been facilitated by a user-friendly graphical interface developed in Python 3. The nozzle of the thrust chamber has been designed using that developed program.