Gelled propellants are safer to handle, have reduced flammability and lower spill susceptibility compared to traditional liquid fuels. However, they are more difficult to atomize and combust, and the gelling agent can cause a loss of specific impulse. EERGC Corporation in cooperation with subcontractor NGST, a leader in gel propellant technology, proposes to develop MMH-based advanced fuel gels that provide higher volumetric specific impulse, incorporate combustible particulate gellants, and have established spray characteristics. To do this we will optimize the physical and chemical characteristics that determine the suitability of gels, including quantitative measures of: 1) The affinity of the components with one another, which affects fluid separation; 2) Physical properties, including surface tension and viscosity, which affect flow and atomization; 3) Chemical properties including energetic content which affects the specific impulse, and the resulting combustion products, which affect the plume emissions signature; 4) Evolution of gaseous products by physical or chemical means, which affects the long-term storage of the gels.This is a departure and advancement over prior work, quantitatively addressing significant issues not previously addressed, particularly the impact of interfacial interactions on heterogeneous gel ingredient interactions and on the surface tension properties and breakup behavior of the gel.
Benefits: The gel fuels to be developed in this proposed SBIR project will be suitable for integration into Common Missile and modernized Hellfire program applications. This is applicable to a number of missile systems such as TOW, Javelin, Hellfire, and potentially Stinger-type systems. Gel propellantsÂ’ potential for enhanced safety and control make them appealing for NASA launch vehicles, spacecraft, and satellites as well as future commercial spaceflight applications. In addition, improved gel technology has wide-ranging commercial applications such as cosmetics, food products, lubricants, etc.
Keywords: fuel gel, particulate gellant, surface tension, rheology, spray formation, monomethyl hydrazine, engine testing
