Introduction

Turbulence, chemical kinetics, and thermal radiation individually are among the most challenging fundamental and practical problems of computational science and engineering. In chemically reacting turbulent flows, these are coupled in interesting and highly nonlinear ways, leading to entirely new classes of phenomena. Interactions between turbulence and chemical kinetics (turbulence–chemistry interaction: TCI) and between turbulence and thermal radiation (turbulence–radiation interaction: TRI) both have profound influences on local and global flame behavior. Numerical simulations that neglect radiation and TRI, or treat them in simplistic fashion, can fail to capture local and global flame ignition/extinction, and yield inaccurate predictions of heat transfer rates (by as much as several hundred percent), temperature (by as much as several hundred degrees Kelvin), and pollutant emissions (especially soot and NO_x). In this chapter an introduction is given to the tools used for state-of-the-art numerical calculation of turbulent reacting flows, including high-level models for fluid flow, chemical reactions, thermal radiation, and interactions of turbulence with chemistry as well as radiation.