In order to realize the optimization of insulation performance of air curtain used in the cold store. The unsteady state simulation of the flow field of air curtain used in the cold store was studied by the CFD software to predict variation of the flow field in the cold store after door and air curtain were opened and the time of the flow field of the cold store arriving to be uniform. The experimental verification was also taken. The simulation results reflected that the temperature of the upper area closing to the door increased first and then decreased, then increased. The intrusive hot air destroyed the original uniform air flow distribution and caused the formation of the swirling eddy. When the whole flow field of the cold store was uniform, the swirling eddy disappeared. The re-circulation moved forward the lower left side of the cold store, which was caused by the intrusive hot air. Local mesh refinement could improve the simulation accuracy and be useful to analyse the flow characteristic of the air curtain. The times of the flow field in the cold store arriving to be uniform predicted by the numerical simulation and experiment after door and air curtain being opened were 5 min and 6 min, respectively. This study will provide useful references for optimization of insulation performance of air curtain.
