Abstract: Supersonic parachutes serve as critical aerodynamic decelerators in deep space exploration missions. Their flexible canopies exhibit characteristics of nonlinear large deformation. The canopy shape significantly affects both aerodynamic performance and mechanical characteristics. The gore number plays a vital role in the inflation and deformation of flexible parachutes. However, the underlying mechanisms remain unclear. To investigate the influence of the number of gores on inflation dynamics and aerodynamic performance, this study performed numerical simulations on Disk-Gap-Band (DGB) and conical ribbon parachutes with 16, 24, and 32 gores, employing the arbitrary Lagrangian-Eulerian fluid-structure interaction (FSI) method. The results showed that for the DGB parachute, parameters remained essentially unchanged as the gore number increased from 16 to 24. However, as the number further increased to 32, inflation time shortened significantly and the drag coefficient increased markedly, while the lateral force coefficient spiked. In contrast, the conical ribbon parachute behaved differently. Its inflation time decreased continuously with more gores, and the opening load rose steadily. The drag coefficient increased moderately, while the lateral force coefficient remained largely unchanged. These findings demonstrate that gore number exerts a nonlinear influence on parachute performances. While adding gores generally improves inflation speed and drag, excessive gores lead to a higher lateral force coefficient for DGB parachutes and a substantial increase in the opening dynamic load for conical ribbon parachutes.

Key words: supersonic parachute, gore number, inflation process, aerodynamic characteristics, numerical simulation