Practical CFD Models for Predicting Lean Blowout and Ignition in Gas Turbine Combustors

Current steady-state CFD combustion codes cannot predict transient combustion phenomena, such as Lean BlowOut (LBO) and ignition in gas turbine combustion systems (e.g. main combustors, interstage turbine burners, and augmentors). In this SBIR, we propose to develop an innovative analytical capability so the combustor designer can address operability issues. The key to predicting LBO/ignition is the use of time-accurate Large Eddy Simulation (LES) analyses and development/validation of accurate spray and chemistry physical models applicable over a wide range of reacting environments. In Phase I, the feasibility of using combustion LES to predict LBO was demonstrated, and model improvements identified. LBO measurements were obtained in single injector tests, and used to validate the LBO predictions. In Phase II, improved spray/atomization models and practical reduced global mechanisms with dynamic coefficients for JP8-air chemistry will be implemented and validated. An innovative ignition model, that includes detailed JP8 kinetics and heat transfer effects to predict flame kernel growth or decay, will be developed and coupled to the LES flow solver. Experimental LBO/ignition data will be acquired on a fuel injector being designed for Rolls-Royce's JSF F136 combustor, and used to validate the software. The final CFD software will be applied to one or more VAATE or JSF combustion configuration(s) selected in consultation with the Air Force.