Initiation and propagation of one-dimensional detonations in aluminum-particle/C2H2/air system

Abstract

This work carries out simulations on the initiation and propagation of aluminum (Al)-particle/C2H2/air detonations in a one-dimensional (1D) planar geometry, based on the Euler–Euler two-phase flow models and the fifth-order weighted essentially non-oscillatory scheme. The effect of Al particles on 1D detonation is studied by changing Al-particle diameter and concentration. It is found that for the two-phase detonation, the initiation is achieved by the sudden transition to a detonation and undergoes an extended overdriven stage, which is caused by the afterburning effect of Al particles in the products. During the steady propagation, the detonations with the proper Al-particle diameter manifest the double-front feature created by afterburning of Al particles in the products. For the big Al particles, the second front is formed more slowly and propagates stably. As Al particles are too big to be ignited downstream, the second front disappears. However, the smaller Al particles make a shorter distance between these two fronts. Nevertheless, as Al particles are sufficiently small, a successful initiation is prone to be more difficult because the evaporation of Al particles absorbs heat.