Fluid-Structure Interaction Study on the Influence of Circular Gap of Parachute on Inflation Performance with Fixed Payload

Abstract

In order to study the influence of circular gap controlled by the tearing force on rescue parachute inflation performance, the Arbitrary Lagrange-Euler (ALE) coupling method is utilized to simulate the inflation process of the circular gap rescue parachute with fixed payload; the contact failure model of the open of circular gap was built by the sewing force of the sewing thread. The canopy structure model influenced by fabric permeability performance is proposed, and the differential pressure of permeable fabric is described in Ergun equation through the textile material permeability test. The numerical results calculated by LS-DYNA are compared with the results of airdrop test and the empirical method of parachute-payloads dynamics, and it is shown that the steady drag coefficient and transient shape during inflation are more consistent with the airdrop test results, and the dimensionless initial inflation time and the maximum equivalent opening shock are more realistic. The stress variations of each gore unity during inflation are investigated. The most dangerous time-space state point during inflation process was discovered. With the study of the influence of the circular gap structure of parachute on inflation performance, the numerical results show the circular gap structure can reduce the opening load and adjust the time of two inflation stages, which reduces the maximum effective stress in dangerous parts and improves the safety of canopy.