Swirl-Stabilized Injector Flow and Combustion Dynamics for Liquid Propellants at Supercritical Conditions

摘要

An integrated modeling and simulation program has been conducted to substantially improve the fundamental knowledge of supercritical combustion of liquid propellants under conditions representative of contemporary rocket engines. Both shear and swirl co-axial injectors were considered. The formulation was based on the complete conservation equations in three dimensions. in addition, general-fluid thermodynamics and transport theories were incorporated to allow for a unified treatment of fluid properties over the entire range of thermodynamic states. Turbulence closure was achieved by means of the large-eddy-simulation (LES) technique. Special attention was given to the fluid behavior in the two-phase and transcritical regimes in which rapid property variations occur. Various underlying physiochemical mechanisms associated with co-axial injector dynamics were studied in detail. These included flow evolution, flame stabilization and spreading, heat transfer, and acoustic response. The effects of design attributes and operating conditions on injector characteristics were assessed. Results have not only enhanced the basic understanding of the subject problem, but also provided a quantitative basis for identifying and prioritizing the key design parameters and flow variables that exert dominant influences on the injector behavior in different environments.