Coupling CFD with chemical reactor network for advanced NO sub(x) prediction in gas turbine

Gas turbine pollutant emissions, especially nitric oxides (NO sub(x): NO and NO sub(2)) and carbon monoxide (CO) are limited to 25ppmvd by the European legislation for natural gas operations. To meet this objective and that of future legislation, it is crucial to have access to numerical tools that could speedily predict NO and CO emissions when operating gas turbines (fuel flexibility, tuning of the fuel distribution between burners...). In this context EDF R&D has been developing a 3D turbulent gas combustion model the past few years. Nevertheless, the introduction of complex chemical kinetics in 3D turbulent combustion code is still too CPU-time consuming for industrial use. Thus, 3D computational fluid dynamics computations, using simple chemistry, are post-treated to generate a 0D chemical reactor network (CRN), which includes a detailed chemistry mechanism. The 3D simulations are used to provide information about the mixing state, and the flow topology including the turbulence effects. The present study focuses on the impact of ambient air conditions (temperature and relative humidity) on NO production by industrial gas turbines. The detailed chemical kinetic scheme is initially validated by laboratory tests on jet-stirred reactor performed in University of Washington.