Process Scaleup of Refractory Open-Cell Structural Foams for Advanced Rocket Engine Injectors

The Air Force is seeking a highly operable aerospace vehicle that can be ready to launch on demand. Hydrocarbon-fueled vehicles offer certain benefits over other propulsion systems. The vehicle is heavier when fueled with kerosene, but because of thenature of the propellant, it is lighter when empty: a benefit in reduced vehicle weight and cost. Also, kerosene costs less to produce and use. Advanced propellant injector materials and designs are required to promote stable combustion with high mixingefficiency. Ultramet has been working with the Air Force Research Laboratory (AFRL) Propulsion Directorate at Edwards AFB to establish the mechanical and fluid flow properties of open-cell silicon carbide foam material produced by Ultramet for potentialuse in injector applications, among others. The flow characteristics show promise for use with hydrocarbon propellants, but the structures fabricated thus far have been limited to relatively small sizes (4