Numerical Modeling of Flame Acceleration and Transition from Deflagration to Detonation Using OpenFOAM®

Abstract

The present numerical investigation aims to study the dynamics of deflagration-to-detonation transition (DDT) in inhomogeneous and homogeneous mixtures. Modeling discontinuities, such as shocks and contact surfaces, in high-speed compressible flows require numerical schemes that can capture these features while avoiding spurious oscillations. For the numerical model, two different solution approaches, i.e., the pressure-based and density-based methods, have been adopted using the OpenFOAM® CFD toolbox. A reactive density-based solver using the Harten–Lax–van Leer-contact (HLLC) scheme has been developed within the frame of OpenFOAM®. The predictions are in reasonably good qualitative and quantitative agreement with the experiments (Boeck et al. in The GraVent DDT Database, 2015 [3]). The DDT phenomena have two major stages; flame acceleration (FA), during which the flow is in the subsonic regime, and the transition-to-detonation stage, in which the combustion wave undergoes a transition to the supersonic state. The present study indicates that it is viable to use the pressure-based algorithm for studying FA, but a density-based method is required for modeling DDT.