Kinetic model for aluminum-sensitized ram accelerator combustion

The chemical nature of the projectile in a ram accelerator device can play a role in the ignition process. We focus here on aluminum. An Al/H/C/O kinetic model is proposed to examine the effect of the vapor pressure of liquid aluminum on the H₂/O₂/CO₂ ignition chemistry. These mixtures are of interest for the superdetonative propulsion mode in a ram accelerator device. The vapor pressure of liquid aluminum, as a film or as droplets, in the 1000-1300 K temperature range and in the 30-200 bar pressure range, although very weak (mole fraction of Al in the range 10^-10-10^-8), is shown to reduce the H₂/O₂/CO₂ ignition delays in some cases by a factor two to three, depending on the conditions of temperature and pressure.