A space-time conservation element and solution element method(CE/SE) was used to simulate the formation and propagation process of two-dimensional detonation with/without obstacles.The detonation mechanisms were analyzed.Influential factors to deflagration to detonation transition(DDT)were evaluated

including the ignition temperature

the tube diameter and the obstacles.Model equation was non-dimensionalized

and the implicit trapezoidal technique was established to handle stiff source term.Results show that the ignition energy is related to the ignition pressure.The higher ignition temperature

the smaller tube diameter or setting obstacles could accelerate DDT process under the condition of small ignition energy.The results offer a reference to study detonation ignition and DDT process.