Development and Validation of a Model for Gelled Hypergolic Reactions

A model that characterizes the flow patterns within gelled hypergolic reaction chambers, and its rigorous validation with prior and current engine development data, is proposed. Phase I modeling will leverage recent breakthroughs associated with hypergolic gel combustion stochastic turbulent dispersion, droplet breakup and a heuristic collision and evaporation methodology. During Phase I a reduced finite rate chemical reaction mechanism for MMH/IRFNA and DMAZ/IRFNA combustion will be conceived. In addition, the heuristic collision model currently in place for hypergolic gelled and ungelled combustion will be replaced with a group interaction stochastic approach. The properties of carbon-loaded MonoMethyl Hydrazine (MMH) fuel gel and Inhibited Red Fuming Nitric Acid (IRFNA) oxidizer gel associated with the Future Missile Technology Integration (FMTI) program will be used to compare the predictions of the conceptual model to experimental results. A second validation effort will be completed using liquid DiMethylAminoethylaZide (DMAZ) and liquid IRFNA data. Prediction of ignition delay time for both propellant combinations using Phase I validation will include existing Army test data. During the Option program detailed design of a test chamber capable of characterizing the spray formation and interfacial tensions associated with gelled and ungelled propellant combinations of interest to the Army will be prepared. Phase II will focus on detailed model refinement and validation using benchmark quality data from a customized test rig. The will be capable of considering both loaded and unloaded fuels.