Combined Linear/Nonlinear Reduced-Order Analysis Tool for Predicting Dynamic and Static Instabilities in Gas Turbine Augmentors

Combustion stability is an important concern in the design and operation of advanced gas turbine augmentors. Engineering design tools are needed that predict potential instabilities in a timely and affordable manner. In this SBIR, a novel, physics-based, reduced-order analysis tool that predicts both dynamic and static stability will be developed and validated. Two types of analysis will be performed: 1) a 3-D linear stability analysis to predict the unstable modes (all types) and 2) a nonlinear analysis to determine limit cycle behavior at a specified frequency. Heat release effects with vitiated air (core flow) and unvitiated air (fan flow) will be predicted by a linear and nonlinear flame response model using detailed kinetics. Other important processes, such as non-uniform mean flows, liquid fuel injection, cooling air, and fuel/air mixing will be included. CFDRC will team up with Georgia Tech (Professor Tim Lieuwen) for the flame response model (in Phase I) and experimental testing (in Phase II). In Phase I, a 3-D linear stability analysis tool will be developed and a simplified augmentor geometry analyzed to demonstrate feasibility. In Phase II, non-linear stability analysis will be implemented and tested. Extensive model improvements and validation will be performed. At the end of Phase II, a GE augmentor system will be analyzed and compared to data.