Modeling high-pressure mixing and combustion processes in liquid rocket engines

Modeling high-pressure mixing and combustion processes in liquid rocket eng ines involves a variety of challenges that include all of the classical clo sure problems and a unique set of problems imposed by the introduction of t hermodynamic nonidealities and transport anomalies, The complicating factor s of chemical kinetics, highly nonlinear source terms, and subgrid-scale ve locity and scalar-mixing interactions must all be considered. The situation becomes more complex with increasing pressure because of an inherent incre ase in the flow Reynolds number and difficulties that arise when fluid stat es approach the critical condition. This paper 1) outlines the fundamental difficulties associated with modeling mixing and combustion processes at ne ar-critical conditions, 2) outlines the theoretical and numerical framework developed to handle these difficulties, and 3) presents the results of sim ulations that lend insight into the intricate nature of the problem. Case s tudies focus on model performance and accuracy requirements, Lagrangian-Eul erian treatments of transcritical spray dynamics, and pure Eulerian treatme nts of transcritical and supercritical mixing and combustion processes.