Large Eddy Simulation of Reactive Flow in a Lab-Scale Liquid Rocket Engine Using a Diffuse Interface Method

Modeling the combustion of liquid oxygen (LOx) and methane (CH4) under subcritical conditions remains challenging due to the complex interactions between two-phase flow, atomization, and combustion processes. This study uses Large Eddy Simulation (LES) with a diffuse interface method to investigate the behavior of a LOx/GCH4 single-injector rocket combustor. The proposed multifluid approach captures phase transition phenomena while maintaining computational efficiency. Numerical results are compared against experimental data, highlighting the model ability to predict flow features, such as the wall pressure distribution and wall heat fluxes. This study emphasizes the importance of accounting for the liquid core, or the dense phase, within the Eulerian framework, rather than relying on Lagrangian injection models, resulting in enhanced predictions of flame topology and heat flux distributions. Although the model exhibits good agreement with experimental measurements, it underestimates heat flux by approximately 10% at the end of the domain, likely due to limitations in the chemical kinetics model. These results show that the diffuse interface method is a promising tool for the simulation of subcritical liquid rocket combustion.