Computational Modelling of MMH/NTO Combustion in a Multi-element Triplet Injector Combustor

This paper presents the computational methodology developed to simulate monomethyl hydrazine/nitrogen tetroxide (MMH/NTO) combustion. A three-dimensional rocket scale combustor domain with multi-element triplet injectors is utilized to study hypergolic flow and flame features. A Eulerian–Lagrangian framework is invoked for continuous phase treatment of combustion gas and discrete phase treatment for both MMH and NTO droplets. A discrete particle-based method (DPM) with finite rate chemistry is employed to study droplet injection, evaporation, and combustion. A description of flow and flame characteristics in three-dimensional RANS framework is presented in this paper. The model captures impinging jets from multiple triplet injectors, and MMH film cooling injection appropriately. It presents physical trends on the core combustion process, as well as the global evolution of temperature, pressure, and droplet spray in the combustor. The focus of the study is to develop a hypergolic combustion model which can be used to predict combustion performance under off-nominal operating conditions. The aim is to extend the model to study the combustion instability aspects of MMH/NTO-based combustors.