Supercritical Combustion of Liquid Oxygen and Hydrocarbon for Staged- Combustion Cycle Engine Technology Development

摘要

An integrated modeling and numerical program has been conducted to substantially improve the fundamental knowledge of supercritical fluid dynamics and combustion of oxygen and hydrocarbon fuels under conditions representative of contemporary liquid-propellant rocket engines. Emphasis was placed on the swirler injector flow dynamics and flame stabilization and spreading. The fundamental characteristics of counter-flow diffusion flames of oxygen and hydrogen, as well as hydrocarbons, were also explored. The analysis was based on the complete conservation equations for a multi-component chemically reacting mixture, and accommodated general-fluid thermodynamics and transport phenomena valid for the entire range of fluid states of concern. Turbulence closure was treated using the large-eddy-simulation (LES) technique. Start-of- the-art closure schemes for subgrid-scale dynamics and turbulence/chemistry interactions were implemented. The effects of design attributes (e.g., injection port size and location, center post recess distance, etc.) and operating conditions (e.g., chamber pressure, velocity, and temperature, swirl strength, etc) on injector characteristics were assessed. Results not only enhance the basic understanding of the subject problems, but also provide a quantitative basis to identify and prioritize the key design parameters and flow variables that exert dominant influence on the injector behavior in different environments.