Multi-Element Gaseous Methane–Oxygen Rocket Combustor Optimization for Modern Space-Flight Technology

Abstract

In the realm of reusable rocket technology, the methane–oxygen propellant combination has gained prevalence in recent years. However, understanding of design parameters affecting the combustion performance of a methane–oxygen combustor is currently limited. The present study proposes a novel analytical and computational approach to design and optimize a combustor. The design of a seven-shear coaxial injector-based combustion chamber is optimized using an in-house developed code line with the aim of minimizing chamber length while preserving chamber performance. Numerical simulations are then carried out to ensure complete combustion within the chamber. Methane–oxygen reactions are modeled using laminar finite-rate and eddy dissipation concept models. An optimized design for the combustion chamber shows maximum characteristic velocity and optimal chamber length near the oxygen-to-fuel mass ratio of 2. The computational study shows that the eddy dissipation concept model can accurately capture the effect of turbulent mixing on gaseous methane–oxygen reactions. The eddy dissipation concept model yielded notable differences in flame characteristics compared to the laminar finite-rate model. The study indicates a need to optimize injector configuration. An optimized injector configuration is proposed by varying its geometric parameters, which exhibits substantial improvement in combustion performance compared to the initial configuration, utilizing practical recess, divergence, and an increased velocity ratio.