Improved Fuel Spray Models for Augmentors

Augmentor stability is critical to the operational performance of military systems that rely on gas turbine propulsion.  For modern close-coupled designs, the distance between the point of fuel injection and the reaction zone is short, resulting in imperfect mixing and vaporization of the fuel droplets.  The ability to predict and/or understand stability in close-coupled augmentors depends on the ability to predict fuel distribution.  Highly resolved simulation of fuel sprays is too computationally expensive for realistic augmentor geometries.  Existing spray models, which significantly reduce computational cost, tend to be inaccurate unless the operator has significant previous experimentally validated experience with the spray condition.  In this project, we will create a tool to develop accurate spray models for augmentors using highly resolved simulations of specific injector and operating condition combinations.  Models derived using this tool can then be applied to accurately predict fuel distributions for realistic geometries with acceptable computational cost.  Our simulation tool utilizes a hybrid approach in which the Volume of Fluids (VOF) method is used to simulate primary atomization and the Discrete Phase Model (DPM) is used to simulate fuel particles in the far field.  We are collaborating with a leading CFD software provider for rapid commercialization. BENEFIT: Technology derived from this project will be in the form of an efficient modeling methodology for spray atomization.  This will decrease development time and cost for future augmentor designs while improving performance.  In addition to improved augmentor modeling, this technology will be relevant to a broad range of engine applications including military and commercial aircraft combustors, internal combustion engines, and power generation engines.