Efficient Implementation of Models for Improved Prediction of Gas Turbine Combustor and Augmentor Robustness

The technical objective of this program is to develop a fast running, subgrid scale turbulence-chemistry interaction model for large-eddy simulation (LES) of aircraft combustors and augmentors that can accurately capture critical phenomena such as extinction and re-ignition effects. To accurately capture these phenomena, this model will be based upon a parameterization of the linear-eddy model (LEM). The LEM is a comprehensive mixing model that separately treats molecular diffusion, small scale turbulent stirring and finite-rate kinetics. Because the model resolves the microscale flame structure, extinction and re-ignition may be accurately captured. Under this program, statistics from this mixing model will be parameterized to form a computationally inexpensive run time model. This parameterization will be accomplished through a unique application of the LEM to a flow configuration designed to capture mean or resolved scale strain effects on the subgrid statistics. The parameterized statistics from this formulation will then be stored either via a look-up table or using the artificial neural network (ANN) data modeling technique, depending on the number of input parameters. The resulting computational model will be a fast running subroutine to provide closure for the LES filtered transport equations that is portable to any CFD flow solver BENEFIT: At the conclusion of this program, CRAFT Tech will have completed the development of an advanced turbulent combustion subgrid model for LES of reacting flows. This effort involves the development of a generalized software tool kit for the generation of user defined functions or subroutine modules for specified combustion problems. These user defined functions may be easily implemented within any CFD flow solver for LES applications. The software tool kit will also be able to generate RANS flow solver user defined functions with only minor changes in the input parameters. Combustion models generated by the tool kit will be applicable to a wide range of military and commercial combustion applications. These applications include gas turbines, power generation systems, furnaces, incinerators, internal combustion engines, etc. The commercial opportunities for this software tool kit are enormous. CRAFT Tech will market this tool kit for license to commercial customers as well as to other CFD flow solver development companies. Since the user defined functions generated by the tool kit will be flow solver independent and completely portable, customers of other CFD flow solver development companies may use the tool kit for their applications. This fact greatly expands the commercial opportunities of the software tool kit.