Abstract: To study the effects of bay door and door opening states on the separation characteristics of internal store, a simplified buried weapon bay-door-missile model is simulated using SST k-ω IDDES method, six degrees of freedom rigid body dynamics equations and overset mesh method under the condition of supersonic inflow. The separation trajectories of missile bodies in different cases were obtained. The results show that, in supersonic flow, shock intersection and shock shear layer reflection are present in the flow field. Considering that the bay door may make the wave structure changed, the trajectory of missile is also changed. The upward pitch angle of missile increases from 0.5° to 6.5°, the right yaw angle of missile increases from 0.3° to 2.5°, and the growth rate of falling speed decreases in later period. Change in door opening state has little impact on dropping displacement and pitch angle, but has greater impact on the yaw angle of missile. It shows that keeping the door away from missile as far as possible can effectively reduce the influence of the door, decrease the yaw angle and improve the separation quality. Key

Key words: fluidmechanics, buriedweaponbay, baydoor, weaponlaunch, oversetmesh, improveddelayeddetachededdysimulation