Chapter 12 - Simulation of direct initiation of detonation using realistic finite-rate models

Abstract

This chapter focuses on the high-fidelity simulation of the detonation initiation process using realistic finite-rate chemistry models. Three experimental methods are used to initiate detonation: (1) flame initiation (2) shock-wave initiation, and (3) direct initiation. In all the three cases, shock waves occur prior to detonation initiation. The direct initiation mode is relevant to the detonation initiation process in a pulse detonation engine (PDE). This mode helps in understanding the various mechanisms in the initiation process and to estimate the critical energy required for a successful detonation initiation. For a cylindrical detonation process in an H2/O2/Ar mixture, propagating waves in three different regimes—supercritical, critical, and subcritical—are calculated according to the value of the deposited energy in the initial conditions. Calculation is based on the use of realistic finite-rate chemistry models and comprehensive thermodynamics models. In the direct initiation experimental mode, model equations are solved by the space-time conservation element and solution element (CESE) method.