Physical Sub-Model Development for Turbulence Combustion Closure

ABSTRACT: The U. S. Air Force needs turbulent combustion models that can be used to simulate combustion in actual propulsion systems at both design and off-design conditions, not models that are only useful for highly idealized problems. With this motivation in mind, Combustion Science & Engineering, Inc. and the Computational Combustion Lab at Georgia Tech plan to enhance current capabilities to simulate combustion in aero-turbine engines, augmentors/afterburners, ramjets and scramjets by improving the limitations of what was found to be the framework that can potentially capture most of the combustion physics relevant to these devices: the Linear-Eddy-Model. This goal includes most propulsion systems of interest to the USAF and, consequently, targets two of four game changing technologies identified by the USAF, hypersonics and fuel-efficiency technologies. To achieve this goal, the developmental work will be guided by thorough Verification & Validation tests. These tests will avoid the practice of using meshes that are so fine that the contribution of the subgrid model to the solution is negligible and will consider various combustion regimes. From a commercial standpoint, the outcome of this research effort will be a software library, a modular API, based on LEM that could be plugged into any CFD code.; BENEFIT: This project will develop a software suite that will enhance current capabilities to simulate combustion in aero-turbine engines, augmentors/afterburners, ramjets and scramjets over a wide range of operating conditions. The product developed in this work will be a useful tool for supersonic and hypersonic vehicle design applications for the U. S. Air Force. Discussions with engine design teams indicate that the capabilities of this project will greatly enhance current design tools in use by equipment manufacturers. Also the market for this product will include gas turbine designers and manufacturers for both military and civilian aircraft. The use of this tool will significantly reduce development costs by eliminating some design iterations and hardware testing, which is quite expensive and time-consuming. Because of the broad range of applicability of the model, it will be useful for other flight vehicle systems, such as interturbine burners, new concepts for high speed aircrafts. It will also be useful to predict blowout and ignition. Therefore, the potential market for this tool is fairly large and ranges over a number of different industries.