开“窗”结构对环帆伞开伞过程影响

With increasing load weight，the inability of single parachutes to ensure safe landing of heavy reentry cap⁃ sules diverts extensive attention to the cluster parachute system which has been successfully applied. However，the interference between the parachutes poses challenges to the cluster parachute design. The new generation of crewed spacecraft has attempted to solve this problem from the perspective of porosity. Due to the difficulty in simulating the inflation process of the cluster parachute，this paper adopts the Fluid-Structure Interaction（FSI）numerical method to conduct numerical simulation of the inflation process of single ringsail parachutes with different porosities without changing the configuration design of the canopy to investigate the influence of the‘windows’structure on aerodynamic performance. The result demonstrates that the‘windows’structure has minor influence on the shape change during the inflation process of the ringsail parachute，with the ratio change of the projected area to the nominal area before and after using the‘windows’structure no more than 15%. For different‘windows’positions and quantities，the best choice to balance the average drag coefficient，opening load，and fluctuation of the drag coefficient is sail position 5 and quantity 25%. The maximum swing angle is reduced by at least 5 °after using the‘windows’structure，and the reduction will increase with the grow in the number of‘windows’；however，no clear patterns between the positions of the‘windows’is observed.