INTERACTION BETWEEN GAS FLOW AND COMBUSTION OF HIGH-PRESSURE METHANE JET TURBULENT FLAME

To investigate the interaction between a jet gas flow and combustion, we developed a three-dimensional numerical model. The flow characteristics [vorticity and turbulence kinetic energy (TKE)] were used to study the effect of the methane jet, while the combustion parameters [hydroxide radical (OH) mass fraction and heat release rate (HRR)] were used to study the effect of combustion. The results showed that the development of the methane jet flame was divided into three stages. In stage I, the methane jet interacted with the premixed flame; in stages II and III, both the flow characteristics and combustion parameters increased. This jet flame was induced by both the methane jet and the combustion. The jet flame velocity increased based on the interaction between the flow characteristics (represent by <i>K</i><sub>v</sub> and <i>K</i><sub>TKE</sub>) and combustion parameters (represent by <i>K</i><sub>OH</sub> and <i>K</i><sub>HRR</sub>). A dimensionless parameter (<i>K</i><sub>0</sub>) was adopted to represent the comparison between the flow characteristics and combustion, i.e., <i>K</i><sub>0</sub> = (<i>K</i><sub>OH</sub><i>K</i><sub>HRR</sub>)/(<i>K</i><sub>v</sub><i>K</i><sub>TKE</sub>). During stage I, <i>K</i><sub>0</sub> < 1 and the high-pressure methane jet played a major role. During stage II, initially, <i>K</i><sub>0</sub> > 1 and combustion played a slightly larger role than that of the high-pressure methane jet; later in stage II, <i>K</i><sub>0</sub> < 1, the high-pressure methane jet played a major role. During stage III, <i>K</i><sub>0</sub> > 1; this result revealed that the combustion played a dominant role while the high-pressure gas jet caused less effects late in stage III of the flame propagation process.