Wall-Mounted Thermally Stable Catalysts For Augmentor Flame Stabilization

Future high-speed missiles need highly efficient turbine engines able to operate over a wide flight envelope. High turbine exhaust temperatures and missile packaging constraints have led to the integration of the fuel injectors into flameholder devices, the so-called close-coupled augmentor. Unfortunately, this causes poor fuel-air mixing with the consequence of poor stability and inefficient combustion. Adding fuel injectors or mixing devices to improve fuel-air mixing results in momentum losses that cannot be tolerated. Bypass flow can be injected to enhance mixing and replenish oxygen, but this can have an adverse effect on the combustion kinetics due to reduced reactant temperatures. Instead, concepts are needed to reduce the dependence on flameholding and mixing devices while permitting the augmentor to operate over a broad range of conditions. TDA Research, Inc. proposes to coat the augmentor surfaces with a thermally stable combustion catalyst. The catalyst will widen the ignition and flammability limits of the reactants to ensure stable and efficient combustion. In Phase I we will conduct experiments to determine the ignition and flammability limits of JP-8/air mixtures with and without catalyst-coated surfaces. In Phase II we will demonstrate the technology in an augmented turbine engine.