Development of GOX/Kerosene Swirl­ Coaxial Injector Technology

Abstract : In developing an advanced liquid rocket engine, injector design is critical to obtaining the dual goals of long engine life and high-energy release efficiency in the main combustion chamber. A joint effort of Sierra Engineering (Sierra) and the Propulsion Directorate of the Air Force Research Lab (AFRL) was conducted to develop a design methodology, utilizing both high- pressure cold-flow testing and uni-element hot fire testing, to create a high performing, swirl coaxial injector for multi-element combustor use. The results of this joint effort have been documented in a series of JANNAF and AIAA meeting papers. The present work studies the hot flow environment specifically the multiple element swirl coaxial injector Numerical simulations were performed with a multiple-phase, pressure-based computational fluid dynamics (CFD) code, FDNS. CFD results produced loading environments for an ANSYS finite element thermal/structural model. Since the fuels are injected at a temperature below its critical temperature, the effect of phase change and chemical reactions needs to be accounted for in the CED model. A homogeneous spray approach with a real-fluid property model was employed in the FDNS code to simulate the spray combustion phenomena over a wide range of operating conditions. Future work, which will not be presented in this paper, will compare these numerical results to planned hot fire test results.