Rapid-Mix Fuel Injector for High Temperature Combustor Applicable to Turboshaft Engines

Conventional fuel injection approaches may not be adequate to meet the unique demands of the JTAGG II Rick-burn/Quick-Mix/Lean Burn (RQL) combustor. A rapid mix fuel injector with innovative features designed to meet the fuel-air preparation requirements of the rich-zone of an RQL combustor is proposed for development in this SBIr project. The fuel and air will be quickly mixed to the design rich equivalenced ratio so that hot stoichiometric mixtures do not impinge on the liner wall and radiation heat loads are substantially reduced. Advanced fuel passage thermal protection to prevent fuel coking will also be incorporated in the injector design. To show overall feasibility of the nozzle, a combined numerical/experimental approach is proposed in Phase I, First, fuel injector designs will be studied using 2-D and 3-D turbulent, reacting CFD computations. The analyses will include advanced finite-rate chemistry with prescribed pdf modeling for turbulent/chemistry interaction wand will show the potential of lower convective and radiation loads to the liner. At least three of the best configurations will be fabricated and experimentally tested using existing rig facilities at Delavan, Inc. Spray quality, ignition, and lean blow-out performance at atmospheric pressure will be measured. In Phase II, the most promising rapid-mix fuel injector design will be optimized and then tested in a full annular combustor rig at Allied Signal Engines.