某圆周缝型救生伞的充气性能研究

Inflation Performance Study of a Rescue Parachute with Circle Gap

为获得新型圆周缝结构救生伞的充气性能,文章采用任意拉格朗日欧拉流固耦合方法对该救生伞进行了充气过程的数值模拟,用空投试验结果验证了该数值方法的可行性。数值结果得到了绕伞衣流场、伞衣外形、运动的动态信息,对数值结果的分析发现初始充气阶段后期流场对上部伞衣影响很大,为充气过程中上部伞衣的控制提供了依据,但是初始充气期救生伞的摆动角度小于充满期。对于结构透气量不对称设计的伞衣,不对称充气是绝对的,圆周缝会首先在结构透气量少的部位张开。结果表明,对不同的圆周缝节点设计不同的开缝力将有助于保持良好的对称充气状态,改变开缝力的设计参数将会改变圆周缝的开缝时间及圆周缝完全张开所需的时长,将达到更好的减载效果。研究结果对圆周缝型降落伞的优化设计有一定的参考作用。

In order to obtain the inflation performance of new rescue parachute with circle gap structure, an arbitrary Lagrangian Eulerian fluid-structure coupling method is utilized to simulate the inflation process of this rescue parachute. The feasibility of this numerical method is verified through airdrop test results. The de- tailed information such as flow field around canopy, canopy shape and movement is obtained from numerical results. The upper canopy is affected significantly by influence of flow field in the later period of initial infla- tion stage, which is the basis of upper canopy controlled in inflation process through the analysis of numerical results. The swing angle of rescue parachute in initial inflation stage is less than the angle of full inflation phase For the asymmetrical structure ventilation canopy, the inflation is absolutely asymmetric; the circle gap will firstly open in small structure ventilation part. The above results show that different open force designs for dif- ferent circle gap nodes will be helpful to ensure good symmetric inflation. Change of open force design pa- rameters will change the time spot of open of circle gap and duration of full open of circle gap, and achieve better load reduction. These results could provide some guidance for optimization design of circle gap structure parachute.