Direct Numerical Simulation of Turbulent Combustion of Hydrogen-Air Mixtures of Various Compositions in a Two-Dimensional Approximation

A technique of two-dimensional direct numerical simulation of turbulent flame propagation in reacting gas mixtures under stationary homogeneous isotropic turbulence conditions is proposed. This technique is based on a detailed kinetic mechanism of combustion of a multicomponent mixture and uses no fitting parameters. It is applied to the calculation of turbulent combustion of a hydrogen-air mixture. A condition is proposed to compare the results of two-dimensional calculations (dependences of flame propagation velocity on turbulence intensity) with the data of actual three-dimensional experiments. The obtained agreement between the calculated and measured dependences confirmed the validity of the proposed condition. The effects of pressure on the flame propagation velocity were considered. The calculated concentrations of the active reaction centers-hydroxyl (OH) and H and O atoms-in turbulent flame are lower than those in laminar flame, which also agrees with experimental results.