钝体甲烷火焰高掺氢比吹熄机理的大涡模拟

High proportion of hydrogen mixed combustion of gas turbine can achieve long-term deep emission reduction and integrate more renewable energy for comprehensive utilization. Based on the open source software OpenFOAM, the large eddy simulation (LES) was used to study the blow-off process of a laboratory scale methane bluff body flame with high hydrogen ratio by using the thickened flame (TF) model and skeleton mechanism. The effect of high hydrogen ratio on the blow-off process was studied by comparing the flames of mixed gases of 30% H₂ and 90% H₂ with the same flow rate. OH-PLIF and PIV were used to measure the flow field and flame structure of bluff body flame. The simulation and experimental results show that the simulation results are in good agreement with the experimental ones, and that the simulation can well capture the flame structure and flow field information. Under high hydrogen ratio, the heat release rate is significantly increased, the flame height is significantly reduced, and the length of recirculation zone is significantly shortened. In the blow-off process, the decrease of heat release rate and stretching effect have influence on blow-off to different degrees. High hydrogen ratio can significantly improve the anti-stretching ability of flame, but the rapid decrease of heat release rate of high hydrogen ratio bluff body flame will lead to a more rapid blow-off process.