Numerical study of parachute inflation process based on smoothed particle hydrodynamics fluid structure interaction method

摘要

>Shortcomings in large deformation calculations by mesh-based numerical methods have been overcome by smoothed particle hydrodynamics method, which is a new meshless algorithm based on Lagrange description and has been widely used in simulations as blasting and impacting, but not been applied in research of engineered fabrics yet. In this paper, a fluid structure interaction method coupling smoothed particle hydrodynamics and finite element was proposed, by which the inflating process of a model parachute was investigated. In the modeling of parachute, the same nodes were shared by beam elements of reinforced belts and adjacent canopy elements to simulate the elastic constraints, while the parachute meshes model was adjusted to satisfy requirement of fluid structure interaction calculation by loading internal pressure, and surrounding flow field was described by smoothed particle hydrodynamics particles. Then, the fluid structure interaction calculating could be realized by contacting algorithm between particles and mesh nodes. The dynamic processes of expanding structure and flow field were obtained by this method. According to the analysis of numerical results, the parachute inflating process could be divided into pre-inflating stage, fully inflating stage and inflated stage; moreover, the noise occurred in wind tunnel experiment could be explained by this method. The “breathing” phenomenon and top collapsing of canopy appeared in numerical results, as corresponded to the tunnel experiment. This new method could be a good supplement in parachute design and research.