Abstract：In order to study the characteristic of turbulent flame in gas explosion, the large-eddy simulation is used to simulate the explosion process with a premixed combustion model based on a small-scale explosion chamber with the size of 150 mm × 150 mm × 500 mm and three cross obstacles. According to the simulation results, the flame structure, the flowing trace of the unburned gas, and their coupled laws are analyzed. The results show that: under the conditions of small-scale, the deformation of the flame induced by obstacles increases the flame area and improves the combustion rate; eddies of unburned gas appear behind the obstacles and the eddies size increase gradually; the flame will be involved into the unburned gas eddies, forming turbulent flame.

Keyword：obstacle;gas explosion;turbulent flame;large-eddy simulation;