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

Sophisticated models will be developed for accurate simulation of gas turbine combustion occurring in the augmentor regions of modern military aircraft engines. The focus will be on the formulation of these combustion models in a large eddy simulation (LES) setting. A sub-filter combustion model covering all the three regimes (premixed, non-premixed and the auto-ignition) of the so-called combustion regime index will be formulated and validated against experimental data. This model will be extended to multi-feed systems that is usually the case in an augmentor environment due to the presence of an additional stream of vitiated air, apart from the usual oxidizer (pure air) and the fuel streams. It essentially means that an approach based on two mixture fractions instead of one will be followed in the development of the combustion models. Finally in phase I, the applicability, feasibility and benefits of a discrete Galerkin (DG) method as a compressible scheme for augmentor flows will be tested. Phase II will include continued development of the combustion models (especially for the multi-feed case) and extensive validation studies against real-life augmentor experiments. BENEFIT: It is envisioned that the successful completion of the entire project will lead to a better augmentor design tool that is founded on detailed chemistry, first-principles based combustion models, the large-eddy simulation turbulence modeling technique, and a highly scalable parallel solver. On the specifics, the project will lead to development of the auto-ignition models in partially premixed combustion, extension and application of the combustion models in compressible LES formulations, and the extension of the models for multi-feed systems. It will further lead to a validated tool that incorporates all these developments, and which will be available for licensing. The models will be formulated such that they can also be incorporated into other CFD codes. Aircraft engine manufacturers and designers will be directly benefited by this project. Any company involved in reacting flows should be potentially interested. The sophistication that will be added to our LES code should create ample opportunities for commercial licensing. The knowledge and exposure gained from this project will enable us to do consulting for the industry.