Effect of the Lewis number and chemical kinetics in modeling of hydrogen combustion

Processes of heat and mass transfer in a turbulent boundary layer in combustion of hydrogen injected from a porous plate to an outer air flow are studied by numerical methods. The used model of turbulence allowed the calculation of the entire flow field including a high-gradient near-wall region. Chemical conversions are modeled by different methods with the aid of equilibrium approximation or a detailed kinetic mechanism. The coefficients of molecular transfer are calculated depending on temperature and composition. Use of kinetics of multistage reactions of formation of the products of hydrogen combustion in air does not lead, in the given case, to noticeable differences in the results. The obtained distribution of turbulent fluctuations allows one to draw a conclusion about flow laminarization in burning. Moreover, the effect of the Lewis number on the position of the flame front and other flow characteristics is analyzed.