A High Turn-Down Ratio, Low Emissions Combustor for Gas Turbine Engines

This proposal describes an innovative, high-efficiency, compactcombustor for lean-premixed, low-emissions gas turbine systems andresponds directly to NASA's request for Innovative technologiesrelating to combustion processes, including fuel injectors, piloting,flameholding techniques for increased and performance and decreasedemissions under SBIR topic A8.02. The concept is based on previouslydemonstrated means for creating high mixing rate regions using multiplediscrete axial vortices in the flow. This injector-mixer-flameholdershows promise for emissions reduction by ensuring rapid and complete,well controlled mixing. Another goal is an axial-vorticity fuelinjection, mixing, and flame stabilization design that passivelycontrols combustion instability and flashback by making the combustionregion insensitive to axial flow oscillations. During previous work APRIhas demonstrated the ability to stabilize flames in a geometry designedto provide open three-dimensional separations. In the Phase I effort theability to control mixing rates in geometry directly suitable to gasturbine combustors was demonstrated. Conceptual designs for combustorsbased on this technology are presented. The Phase II effort will takeadvantage of the axial vorticity mixers and flame stabilizers tocomplete the design and test of a lean-premixedfuel-injector/flame-holder for gas turbine systems.