Research On Fluid Structure Integration Of The Parachute During Opening Processing

Parachute is a very important aerodynamic decelerator. Working process of the parachute involves types of subjects,such as flight dynamics, aerodynamics, structural dynamics and so on.Opening process is an interaction of aerodynamics and structural dynamics by a state of rapid large deformation,which is the most complex process of the working process.In this paper,it is carried out a preliminary research by the calculation of fluid structure integration during opening precessing of parachute.The study focused on the following aspectsd: (1)It's summarized in deal the process of research of fluid structure integration of parachute and pointed out the grid-based computation fluid dynamics (CFD) and vortex method is currently the mainly research method to slove the problem during the opening processing.(2)It's summed up structural mechanics equations, computational fluid dynamics equations and related coupling methods during opening process.(3) It's established a quasi-three-dimensional based on parachute C-9, and simulated and analysis the shape changing, fluid distribution, stress changing of the parachute by soft ware LS-DYNA by the condition of steady flow.(4) It's established the models of three kinds of parachute(the parachute with no gas transmission, the parachute with a top vent and the parachute with a top vent and circular gaps) by soft ware fluent in terminal decent, and simulated the flow filed, the velocity flied and the pressure flied and got comparation and analysis.The main conclusions of this paper are that: (1)it's produced a pair of vortex which is equal and opposite inside and outside the canopy.The vortex inside the canopy gradually decreases and moves to the top of the canopy.The vortex outside the canopy gradually grows up and moves to wake of the fluid.(2)Top of the canopy inflates firstly and expand to the end of the canopy during inflating process and presents a phemomenon of changing of the breathing. (3) It indicated that increasing permeability of the canopy appropriately was beneficial to the stability of the parachute on the premise of the falling speed with control.