Modeling and Diagnostics of Gel Propellant Mixing and Combustion

The capability to experimentally characterize the flow patterns of gel engine mixing and combustion, as well as validate numerical simulation technology that predicts detailed engine operation, is proposed. The Phase I analysis methodology will be basedon 1) advanced gel rheology behavior simulation expertise; 2) existing bipropellant and pintle motor system modeling software; and 3) state-of-the-art liquid bipropellant combustion transient CFD methodology. Numerical simulations will focus on identifingtrade-offs between MMH gel carbon loading versus plume signature, matching variable temperature fuel and oxidizer gel rheology to achieve consistent mixture ratios, refining current injection techniques (both vortex and pintle) for improved engineperformance, and optimizing nozzle shape to maximize Cf. Existing FMTI test data will be utilized to validate gel motor flow phenomena sub-models. The Phase I modeling effort will be relied upon to select the most appropriate laser diagnostics approachfor quantifying the mass concentrations and temperatures within the gel combustion and associated plume expansion processes. During the Phase I option program the methodologies developed here will be applied to ongoing FMTI development activities. InPhase II, a comprehensive laser diagnostics system will be assembled within existing AMCOM gel motor test operations. This system will be utilized to generate benchmark quality gel combustion data suitable for identifying gel combustion refinements andvalidating high fidelity gel propulsion numerical simulations.The developed analysis techniques, laser diagnostics, and test hardware will have immediate impact on AMCOM sponsored smart propulsion initiatives and propulsion manufacturers in the design,analysis and testing of gelled propulsion systems. Other applications include numerous industrial pneumatic actuation control systems and bipropellant throttling within the marine and space propulsion industries. CFDRC's close working relationships withpropulsion system manufacturers (TRW, Atlantic Research, Aerojet, Thiokol, etc.) assures rapid technology/expertise transfer and rapid Phase III commercialization, respectively.