Applications Of The Laminar Flamelet Model For The Numerical Simulation Of Diffusion Turbulent Combustion

In this thesis, firstly, the strain rate effects on the counterflow hydrogen-air diffusion flames are numerically studied. Results indicate that the maximum flame temperature and the flame width decrase with the strain rate.Secondly, the partition tables of the laminar flamelet are built up by using the Chemkin software package, the FlameMaster software package and the modified source code of Chemkin. In the partition table, the mixture fraction is used as the independent variable and the scalar dissipation rate is used as the parameter. By using the assumed Beta probability density function, the summary table of the laminar flamelet can be generated.Thirdly, the laminar flamelet model is used to simulate the diffusion turbulent combustion, the effects of the selection of Lowis numbers and the scalar dissipation rates on the non-premixed hydrogen-air turbulent combustion processes are studied. After comparing the simulation result and the experimental data，it is revealed that the turbulent combustion process can be better described if all the Lowis numbers are set equal to one, and the selection of scalar dissipation rate will not cause much impact on the calculation of the turbulent diffusion flame. Altogether the consequences indicate the possibilities of using the laminar flamelet model for the simulations of diffusion turbulent combustion.