Large‐Scale Quasi‐DNS of Mixed‐Mode Turbulent Combustion

Abstract

AbstractIn many applications like gas turbines, the combustion process can take place in partially‐premixed environments, where fuel and oxidizer are not fully mixed before combustion. These partially‐premixed or mixed‐mode flames have become a focus of combustion research in the last few years. In this work, a quasi‐DNS of an experimentally measured burner configuration has been conducted. The simulation employs a complex reaction mechanism and detailed molecular diffusion coefficients for each chemical species. Due to the highly resolved numerical grids and the detailed thermo‐physical and chemical properties, the simulation results allow to characterize the flame with the help of flame markers in greater detail than the experiments can provide. The investigated flame exhibits characteristics of a premixed flame near the nozzle. Further downstream both premixed and non‐premixed combustion modes become equally important in terms of the heat release rate. The dataset from the simulation also allows to form joint probability density functions of commonly used control variables to study their correlations depending on the combustion regime.