The Dynamic Simulation And Analysis For A Parachute-payload System During The Recovery Process

Parachute deceleration systems are a primary means of recovery and landing of air and space vehicles. Their performance characteristics must be known and considered in selecting and designing any parachute recovery systems. In this thesis the problems relative with safe reliability of parachute recovery system of manned spacecraft are commenced, the coning motion of the systems in steady decent are studied emphatically; In view of multibody dynamics, two different dynamic modeling principles and methods of parachute systems have been discussed, and their dynamic characteristics are analytically compared.By synthesizing and applying dynamic principles and analytical methods of analytical dynamics and multibody dynamics, and by taking full advantage of configuration feature of general parachute-payload systems, an eleven degrees of freedom constrained multibody dynamic model of the system is developed. With appropriately selecting the partitioned generalized velocity, the bridle between the parachute and payload can be considered as elastomer or rigid body in a single simulation program. It is presented a general research method for analysis of different parachute-payload systems.The added mass of parachute is studied, including its definition, determination methods and applications. The dynamic stability analysis for parachute recovery system of manned spacecraft during recovery and landing process is carried out. Two involved dynamic models and equations of motion are depicted, some valuable conclusions are obtained through numerical simulation calculations and analysis.In allusion to the coning motion of parachute systems in steady decent, the impact of several factors upon the motion forms of the system are discussed, and the influence of the different aerodynamic parameters on the system's coning motion are analyzed significantly. On the base of these, theoretical formulae of the system's steady coning motion are deduced to validate the model's correctness. These methods are applied to Shenzhou manned spacecraft recovery system. Some useful conclusions are gained by a simulation, which provide references for the stability analysis of manned spacecrafts in steaty decent.