Large eddy simulation of turbulent non-premixed oxy-fuel jet flames with different Reynolds numbers.

• LES-SWF well predicts oxy-flame characteristics across a wide Re range. • Higher Re reduces radial flame size, enhancing effects of vortex on reaction zone. • Increasing Re weakens the beneficial effect of preferential diffusion of H 2. • Adverse effect of CO 2 on combustion increases with increasing Re. Due to differences in the physical and chemical properties of CO 2 and N 2 , along with a reduction in the momentum ratio between oxidant and fuel streams, the local extinction of oxy-fuel flames is significantly more pronounced compared to conventional air–fuel flames, which poses challenges in the design and operation of oxy-fuel burners. This study further validates the species-weighted flamelet/progress variable (FPV) model proposed in previous work [Jiang et al., 2023], particularly in oxy-fuel flames characterized by highly local extinction. Large eddy simulations were conducted on the Sandia oxy-fuel jet diffusion flame at various Reynolds numbers. The predictions are systematically compared with experimental data, and the influence of Reynolds number on local extinction is thoroughly analyzed. The results demonstrate that the numerical simulation effectively predicts mean temperature, species mass fractions, differential diffusion parameters (Z HC), and local extinction in oxy-fuel jet flames across a wide range of Reynolds numbers. The errors in predicted mean temperature and mass fractions exhibit a slight increase with rising Reynolds numbers, yet remain below 15 %. As the Reynolds number increases from 12,000 to 18,000, the predicted peak Z HC decreases by 30 %, and the beneficial effect of preferential diffusion of H 2 weakens, while the adverse effect of CO 2 on combustion becomes stronger. [ABSTRACT FROM AUTHOR]