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A study on "Bottleneck" Phenomenon during Parachute Inflation

Sol Song Pak*, Chol Min Ri, Won Hak Kim, Nam Song Pak and Hyong Gyu Jon

In this paper we focus on Fluid–Structure Interaction (FSI) modeling and performance analysis of the large-scale parachutes to be used with the spacecraft. We address the computational challenges with the latest techniques developed by the TAFSM (Team for Advanced Flow Simulation and Modeling) in conjunction with the SSTFSI (Stabilized Space–Time Fluid–Structure Interaction) technique. The Arbitrary Lagrangian Eulerian (ALE) Method-a Fluid-Structure Interaction (FSI) model, was used to simulate the inflation process of a main parachute (a ring sail parachute, which was used in manned spacecraft) in an infinite mass situation. The dynamic relationship between canopy shape and flow field was obtained and the adverse inflation phenomena such as asymmetric inflation and whip were observed in simulation results. The “bottleneck” phenomenon in inflation process was found and verified by physical tests. Based on the analysis of calculation results, it is found that the large canopy area, the complicated canopy structure or high inflation speed can block the air mass into the parachute, which can cause the “Bottleneck” phenomenon. But the necessary occurrence conditions of the phenomenon need to be studied in future. The present work is significant for explaining parachute working mechanism and preventing its failure. In this paper we discussed a method to prevent “Bottleneck” phenomenon in the case of the large-scale parachute.