Developing a Turbulence-Inspired Zonal Combustion Modeling Approach, Implementing the CRNs in Turbulent Diffusion Flames

Abstract

Computational modeling of the combustion systems not only depends on the flow field typology but also requires well considering the turbulence-reaction interactions. Complex combustion chambers can increase numerical costs dramatically. This paper addresses a novel CFD-based chemical reactor network (CFD-CRN) integrated approach to predict combustion byproducts with high accuracy. This methodology uses turbulence intensity as a determining factor to generate clusters of reactors. The CFD simulations were performed with fine grids using the GRI-Mech 2.11 methane-air combustion mechanism with 277 elementary reactions of 49 species. The GRI-Mech 3.0 including NO formation and reburn chemistry, with 53 species and 325 reactions, is used for the CRN analysis. Implementing the CFD-based CRN, the authors found that the rate of production of NOx from the prompt, thermal, and N2O pathways are calculated as 47.37%, 22.18%, 30.45%, and 40.24%, 29.13%, and 30.63% for the Sandia flames D and E, respectively. The computational fluid dynamics reports for those pathways are predicted as 50.39%, 19.78%, 29.83%, and about 43.58%, 28.45%, and 27.97% entire the Sandia flames D and E, in order. It is deduced that the application of the hybrid CFD-CRN in combustion systems is not only reliable for its high accuracy but also is noticeably efficient for fewer CPU requirements and numerical costs, especially in industrial combustion systems.