Numerical simulation of the combustion of nano-aluminum in carbon dioxide

The ignition and combustion characteristics of nano-aluminum in CO2 were studied numerically using CHEMKIN-PRO and a detailed reaction mechanism. The effects of initial temperature on the combustion performance of nano-aluminum in either gas phase or liquid phase were analyzed. Numerical results show that increasing the initial temperature promotes the ignition of nano-aluminum. When nano-aluminum is in gas phase, the two-stage ignition regime disappears gradually with the increase of initial temperature because the initial system energy increases. In contrast, if nano-aluminum is assumed in liquid phase, the two-stage regime of ignition shows a reverse tendency. In addition, the calculated laminar flame speed reaches SL = 32 m/s at an initial temperature T0 = 2100 K. The key reaction pathways of nano-aluminum in CO2 are Al + CO2 = AlO + CO, Al2O3 = Al2O2+O, and Al2O2 = Al2O + O. Al2O2 is a key intermediate species in nano-aluminum-CO2 system since most of O atoms are produced from its decomposition.