Subgrid Linear Eddy Mixing and Combustion Modelling of a Turbulent Nonpremixed Piloted Jet Flame

A linear eddy model for subgrid mixing and combustion has been coupled to a large eddy simulation of the turbulent nonpremixed piloted jet flame (Sandia Flame D). For the combustion reaction, simplified, single-step, irreversible, Arrhenius kinetics are used. The large scale and the subgrid structure of the flow are compared with experimental observations and, where appropriate, with a flamelet model of the flame. The main objective of this work is to demonstrate the feasibility of the LES-LEM approach for determining the structure of the subgrid scalar dissipation rate and the turbulence-chemistry interactions. The results for the large- and subgrid-scale structure of the flow show a reasonable agreement with the experimental observations.