Numerical investigation of deflagration to detonation transition in closed ducts under various working conditions

摘要

In the present study, a turbulent deflagration to detonation transition in gas mixtures of H-2-O-2 with a vertical concentration gradient in a closed duct was investigated numerically using OpenFOAM package. In this regard, the computational model is based on accounts for deflagrative flame propagation, autoignition as well as the formulation of a reaction progress variable. The simulation was carried out with several reaction mechanisms such as Warnatz, Oran, O-Conaire, Detailed, Skeletal, and GRI 2.11 mechanisms. It works on relatively coarse grids and indicates a good agreement with available experiment data when the O-Conaire mechanism was used. After validation of the numerical results, the DDT behavior was investigated under different working conditions including detonation in wavy closed ducted. Furthermore, the effects of the initial ignition power were investigated. The results were shown that changes in the duct geometry and initial ignition power have sensitive effects of DDT structure.