Abstract
The effect of the initial pressure and the initial fuel, O_2 and N_2 concentrations on a relationship between the initial temperature and the ignition delay in a constant-volume vessel was discussed using a detailed chemical kinetic model of n-heptane generated by KUCRS. When the initial temperature increases, the branch of C_7H_<14>OOH removal into the second O_2 addition and the decomposition is more sensitive to the O_2 concentration, and thus, the LTO preparation phase is more affected by the O_2 concentration. When the O_2 concentration increases, due to the activation of the second O_2 addition to C_7H_<14>OOH and the less accumulation of intermediates, the LTO end temperature increases. The TIP phase is controlled by the rate of H_2O_2 (+ M) = OH + OH (+ M). When the pressure increases, the rate of this reaction increases by the dependence order of about 2, and due to the proportional increase in the whole gas concentration, the ignition delay shortens by the dependence order of about 1 in the blue-flame dominant region.
