Time-average character of gas-liquid two phase swirl combustion

In order to provide a reference of the actual spray evaporation and combustion, Three-dimensional swirling spray combustion under different condition were studied by Direct Numerical Simulation (DNS). The gas combustion was modeled by an adaptive one-step reaction mechanism, the droplets were tracked in Lagrangian framework and the evaporation was described by infinite heat conduction model. We have learned the time-average character for both gas phase and liquid phase. It was found that there is mutually reinforcing effect between the combustion and the central recirculation zone (CRZ). Co-swirling leads to a stronger central recirculation zone (CRZ), but there will be a smaller outer recirculation zone (ORZ). The reaction rate is much higher and evaporative cooling effect is more obvious in rich combustion. Turbulence inflow will make contribution to higher dispersed droplets and smaller droplets.