Simulation research in measurement of opening overload of life-saving parachute in dummy high-speed airdrop

In this paper, CFD and ADAMS virtual prototyping technology were used to simulate the whole airdrop process. Three cases with different hanging positions and hanging postures were simulated. We divided the whole airdrop process into four stages, leaving cabin stage, pull-out stage, opening stage and stable landing stage. Firstly, the complex aerodynamic characteristics of trunk dummy were calculated by CFD method. Before pullout parachute, leaving cabin stage, the varying attitude of dummy was simulated by dynamic mesh method using CFD software. Secondly, the pull-out stage and opening stage model were set up in ADAMS. In pull-out stage, parachute was discrete into damping spring and mess particle connection model. The opening stage and stable landing stage was also simulated in ADAMS. Aerodynamic drag characteristic and additional quality were deal with empirical method. Lastly, the simulate results were compared with experimental results and then analyzed on phase plane. These simulation results match experimental results well in temporal domain. There two peaks in overload data, one is pull-out peak, and another is opening peak. They have a negative correlation, which also meet the test results well. Phase plane was established by dummy angular and angular velocity. On phase plane, the state of dummy motion exhibit significant differences in leaving cabin stage, pull-out stage and opening stage. On phase plane, the opening shocks of dummy were smaller, which could be considered as favorable parachute opening area. It shows that there is a strong dependence between the dummy attitude, angular velocity and the overload of dummy center at the parachute opening moment. However, the dummy hanging position and hanging posture in cabin almost have no effect on overload data. In summary, the model of this paper can simulate all the airdrop process. Using this simulation method, we reproduce the problem in life-saving parachute and dummy system airdrop, and analyzed the issue. We found a good regularity on phase plane, which show us a favorable dummy attitude when parachute is opening.