Combustion Stability Innovations for Liquid Rocket Engines

While guidelines for stable combustion in certain engine cycles and propellant combinations exist; there is no proven, mechanistic predictive model, particularly for high-performance liquid hydrocarbon-fueled engines. IN Space and Purdue propose to fill this critical need by developing a “testbed” consisting of 1) a predictive combustion stability design tool to mitigate the risk of generating instabilities in new designs or analyzing instabilities in existing designs of oxidizer-rich staged combustion (ORSC) engines and 2) a stability verification protocol to assess stability margin during full-scale engine testing. Analytical and experimental testbed elements needed to bring about these developments include subscale experiments at real-scale conditions to provide validation data; advanced CFD modeling based on detached eddy simulation, Reynolds-Averaged Navier-Stokes and linear and non-linear Euler equations to provide fundamental understanding as well as to derive and test combustion response submodels for engineering analysis; engineering state-of-the-art level design analysis for data interpretation. State of Indiana matching funds will be used to construct and test a subscale combustor experiment needed to gather stability data in Phase I. The Phase I effort provides a strong foundation for a Phase II effort, which will focus on further product improvements and validation using a test article at full-scale conditions.