Experimental and Computational Results of Distributed Combustion for Application in Current Gas Turbine Engine Combustor Architectures

Abstract

Current development and testing has lead to a fuel/air injection system for application in gas turbine engines that produces ultra low emissions and stable, lean combustion. The system is designed to operate with current combustor architectures similar to existing gas turbine engines. This paper presents both experimental and numerical test results demonstrating the benefits of such technology including extremely low emissions of NOx, CO, and un-burned hydrocarbons (UHC). Primary focus is on experimental results demonstrating reaction distribution and emissions. Numerical confirmation of flow field dynamics was used to develop an understanding of the re-circulation rates within the combustor and impact on reaction behavior. Several design configurations were tested to investigate the effects of aerodynamic stagnation point and fuel placement with respect to the aerodynamic shear layer produced by the swirling flow field. Test conditions were varied, including inlet air temperature and injector pressure drop for monitoring effects on the operating envelope of distributed reaction and on lean blow out limit. Results demonstrate the improved performance of a system capable of operating in a flameless or distributed reaction mode over that of a typical lean burn system.