可压缩弹射出伞模型及仿真

Compressible Model and Simulation of Ejecting Parachute

火工装置常用于降落伞的强制开伞。针对柔性降落伞织物的可压缩特性,建立了弹射筒可压缩弹射出伞模型并开展了仿真计算,仿真结果与传统刚性模型进行了对比,表明可压缩弹性模型与实验数据更吻合,具有更高的准确性。同时研究了火工药剂参数、弹射筒几何结构及伞包材料特性对弹射力、伞包拉力及弹射速度的影响,发现火工装置初始容腔增大或活塞尺寸减小均会降低弹射推力;而伞包材料弹性使伞包受力小于并滞后于顶盖受力,伞包弹性越好,包装密度越小,越有利于降低顶盖速度和伞包受力。本文的可压缩弹射出伞模型为火工装置及伞包设计提供了一种新的设计分析思路。

The pyrotechnic devices are usually used for coercive opening parachutes. Based on the com- pressible property of flexible parachute textile, a mathematic model is established and the ejection process of parachute bag is simulated in this paper. The calculation results are compared with the results by traditional rigid model and the test results, which shows that the result is consisting well with the test data and the accuracy is improved by the compressible model. The effects of powder parameters, geometry structure of mortar and properties of parachute bag material on the ejection thrust, the para- chute bag tension and the tip velocity are investigated. The result shows that the larger original-volume and the less size of piston can decrease the ejecting force, the bag drag is smaller than and lags the tip force for the fabric elastic property, and the higher elasticity and the lower packing density can decrease the tip velocity and the parachute bag tension. The compressible model provides a new designing propos- al on pyrotechnic device and parachute bag.