Integrated modular design and analysis of liquid propellant rocket engine working on liquid methane-oxygen expander cycle

Abstract

Liquid Propellant Rocket Engine is still the most widely used propellant system since it provides higher thrust and specific impulse due to its higher chemical energy stored. As this technology is maturing, present developments in rocket engines demand overall design flexibility, simplicity, and reliability while preserving higher performance. Modular design is such a concept that divides a system into small modules which can individually be created and modified. This work aims to use such a concept for designing a high-performance rocket engine working on a liquid oxygen-methane expander cycle and check its feasibility. Chamber Pressure and Desired Vacuum Thrust value were taken as 3.5 MPa and 60 kN respectively. Methane is used as fuel due to its ease of availability, low manufacturing cost, and high energy density. All major components for the engine including the combustion chamber assembly, nozzle, turbopump assembly, regenerative cooling jacket, and injector were modeled. More attention was given to critical components like an injector, cooling channels with regenerative cooling analysis, and turbopump assembly. MATLAB code was developed to perform heat transfer analysis in cooling channels. The code was validated by comparing previous experiment data available from literature to check its accuracy.A geared-shaft, axial turbine, centrifugal impeller turbopump was designed to deliver high pressure. Geometry was tested with different aspect ratio cooling channels as well as constant aspect ratio cooling channels. Cooling from variable aspect ratio channel was found superior compared to constant aspect ratio channels with less than 15% to 30% pressure drop compared to Constant aspect ratio cooling channels. Based on analysis ideal aspect ratio for maximum cooling was determined. Parametric calculations and detailed design are presented in this paper by using modular concepts and with the most favorable engine design.