Wall-Mounted Thermally Stable Catalysts For Augmentor Flame Stabilization

High-performance turbine engines are an attractive means to power high speed aircraft and missiles. Although the basic turbine generates substantial thrust, an augmentor (or afterburner) provides even greater thrust margin and can accelerate the vehicle to much higher cruise Mach number. Unfortunately, achieving stable combustion in the augmentor can be difficult, especially when the inlet flow pressure and temperature are both low such as at low Mach or high altitude flight conditions. Further, the flow into the augmentor will be partially depleted of oxygen by the primary combustor upstream of the turbine, reducing the kinetic rates and substantially narrowing both the ignition and flammability limits. Catalysts can dramatically increase kinetic rates by causing combustion to occur along a pathway with much lower activation energy, but they often deactivate at high temperature. Fortunately, TDA has developed stable combustion catalysts with long life at high temperature. In Phase I we conducted laboratory experiments to demonstrate catalytic combustion of fuel-air mixtures at augmentor flow conditions. Then, we coated a flameholder with our catalyst and extended the combustor operating range. In this Phase II project we will coat augmentor flameholder and pilot surfaces with our catalyst to improve combustor performance and operability.