SBIR-STTR Award

The objective of this proposal is to demonstrate the feasibility of integrating numerical testing with benchmark measurements for developing a validated accurate numerical code for turbine augmentor combustion modeling. 1- Feasibility of using our FPVortex code, that has been used in similar applications with proven record, for additional simulations will be studied. The code will be used to predict six different operating conditions, representative of the military engine flight envelope. Component numerical simulations will include liquid fuel spray droplet technology where successful prediction of the heat release characteristics in a combustor would provide combustion stability information. Including behavior of two phase flow injection, development of the gas-phase and liquid-droplet velocities , and the flame structure and the heat release profiles in the primary zone of the combustor. Key operational factors such as attached vs. lifted flame structure, and characterization of stable vs. unstable flame will be established. 2- A feasibility study will be performed to determine whether a sub-scale augmentor (or a segment) model should be designed and built, or a full-scale system must be employed for performing benchmark measurements to be used for validation in phase II of this research. 3- Perform a review of the state-of-the-art for predicting combustion instabilities in turbine augmentors. 4-Evaluate the feasibility of using high frequency pulsed fuel injection for increased mixing and active stability control of the augmentor combustion. The methodology described in this proposal, once successfully accomplished, will provide the opportunity for more efficient numerical modeling of turbine augmentor combustion flow that is validated. This will lead to economical and accurate design, efficient testing, and analysis of jet engines with augmentors. The end result of this work is expected to be reduced development costs and improved performance for all military and commercial jet engines including those without an augmentor. Furthermore, improved (augmentor) combustion will play a critical role in the increase in thrust of (military) jet engines and will extend their flight envelope

This proposed Phase II modeling effort is designed to improve the accuracy of numerical predictions of military gas turbine augmentors through a coordinated program of physics-based modeling improvements within the selected, state-of-the-art Computational Fluid Dynamics (CFD) flow solver (named FP-Augmentor), and a concurrent test program to provide essential validation data for key models. The major modeling tasks will include implementation of efficient chemistry models for jet fuels, validations, and applications to predict flow in high-performance gas turbine augmentors, using geometry and flow information provided by AEDC and turbine manufacturer organizations. The major experimental task includes the testing of a single spray bar, representative of configurations currently in use in industry, and the detailed measurement of cold flow spray droplet characteristics as measured using advanced optical instruments for local velocity and droplet diameter data. Limited combustion experiments will be conducted with the spray bar, in the year two of this study