Based on WALE model and Zimont premixed combustion model

a large eddy simulation(LES) had been applied to study the characteristics of flame of gasoline-air mixture explosions in a closed narrow-long space with an inner size of 0.187 m×0.187 m×2 m. The results of large eddy simulation and RNG k-e model were compared to experimental data and the comparisons confirmed that LES is capable to simulate gasoline-air mixture explosions in closed narrow-long space. The conclusions show that:(1) LES accurately reproduced the formations of flame structure throughout propagation. (2) Two kinds of symmetrical vortices in opposite direction were created in the burned region after the flame front. The kind of symmetrical vortices near the pipe surface contributes to the formation of Tulip flame and the opposite symmetrical vortices that come after the flame further propagation contributes to the collapse of Tulip flame. (3) At the normal concentration of gasoline-air mixture explosion

the gas flow remains positive in the unburned zone and the explosion overpressure

the flame propagation speed and the flame structure have significant coupling relation.