Transported PDF simulations of turbulent CH_4/H_2 flames under MILD combustion conditions

摘要

Transported probability density function (TPDF) simulations have been carried out for turbulent non-premixed CH_4/H_2 flames of jet-into-hot-coflow (JHC) burner, a typical model to emulate moderate or intense low oxygen dilution (MILD) combustion condition. Two cases with different O_2 levels in the coflow stream, namely HM1 and HM3, are simulated with the differences between MILD combustion and hot-temperature combustion being analyzed. With a detailed 25-species mechanism and the EMST mixing model with C_Φ = 2.5, the TPDF simulations can well predict the temperature and species distributions for both cases, demonstrating the great potential of TPDF simulations for investigating the physio-chemical process in kinetics-controlled and low-temperature combustion. The effects of composition boundary condition distribution and mixing model constant on the predicted flame characteristics are also investigated and quantified.