摘要
针对空投航行体和火箭助飞航行体高速入水过程中遭受巨大的冲击载荷,可能导致的结构损坏、弹道失控等问题,提出了一种开槽包裹式缓冲头帽,用于保护航行体入水过程中的结构安全。首先,给出了缓冲头帽的详细设计参数,基于任意拉格朗日-欧拉算法,建立了航行体带缓冲头帽高速入水数值模型,并对该数值模型的正确性进行了验证。然后,在此基础上,研究了不同入水角度下,空泡流场的演变过程,分析了入水时缓冲材料的应力分布情况。最后,探究了不同入水速度和入水角度下缓冲头帽的降载性能。结果表明,数值计算所得空泡形态与实验图像基本吻合,且数值计算和实验测试所得的冲击加速度变化趋势基本一致,两者轴向加速度峰值相对误差为6.72%,径向加速度峰值相对误差为7.52%。航行体装备所设计的缓冲头帽以300 m/s的速度垂直入水时轴向降载率为22.17%;以100 m/s的速度60°入水时,轴向降载率为31.83%,径向降载率为66.80%。
In order to solve the problems of structural damage and ballistic runaway caused by huge impact loads suffered by air-drop vehicles and rocket-assisted vehicles during high-speed water-entry,a slotted wrapping buffer head cap was proposed to guarantee the structural safety of the vehicles during water entry.Firstly,the structural composition and detailed parameters of the head cap were given,and a numerical model for the high-speed water-entry of the vehicles was established based on the arbitrary Lagrangian-Eulerian(ALE)algorithm.The Lagrangian viewpoint was used to solve the small deformation of the vehicle and the head cap,and the Eulerian viewpoint was used to capture the large deformation of the free surface such as water and air,thereby overcoming the problems that the Eulerian mesh was not accurate enough to solve the structural deformation and the numerical oscillation caused by mesh distortion in solving large deformation problems by the Lagrangian mesh.On this basis,the evolution processes of the cavity and flow field around the vehicle entering the water with the head cap at different angles were studied by numerical simulation,and the interaction process between the head cap and the water was given.Furthermore,the distribution of effective stress of the buffer was analyzed when it entering the water vertically and obliquely.Finally,the load reduction performances of the head cap when the vehicle entered the water at different velocities and angles were investigated.The results show that the cavities obtained by the simulation are basically consistent with the experimental images,and the change trends of impact acceleration are basically consistent with the experimental results.The relative error of the axial peak acceleration between the numerical simulation and experiment is 6.72%,and the relative error of the radial peak acceleration is 7.52%.The ratio of axial load reduction is 22.17%when the vehicle enters the water vertically with a head cap at 300 m/s.At the same time,the ratio of axial load reduction is 31.83%and the ratio of radial load reduction is 66.80%when the vehicle with a head cap enters the water at 100 m/s and 60°.So this research has a certain guiding role in the design of new load-reduction structure.
作者
施瑶
刘振鹏
潘光
高兴甫
SHI Yao;LIU Zhenpeng;PAN Guang;GAO Xingfu(School of Marine Science and Technology,Northwestern Polytechnical University,Xi’an 710072,Shaanxi,China;Key Laboratory of Unmanned Underwater Vehicle,Ministry of Industry and Information Technology,School of Marine Science and Technology,Northwestern Polytechnical University,Xi’an 710072,Shaanxi,China)
出处
《爆炸与冲击》
EI
CAS
CSCD
北大核心
2022年第12期93-105,共13页
Explosion and Shock Waves
基金
国家自然科学基金(U21B2055,52171324)
中央高校基本科研业务费(3102019JC006)。
关键词
航行体
高速入水
缓冲头帽
降载性能
任意拉格朗日-欧拉算法
vehicle
high-speed water-entry
buffer head cap
load reduction performance
arbitrary Lagrangian-Eulerian algorithm
作者简介
第一作者:施瑶(1988-),男,博士,副研究员,shiyao@nwpu.edu.cn。
