高纯铜界面Rayleigh-Taylor不稳定性扰动增长的数值模拟  

Numerical Simulation of Rayleigh-Taylor Instability Perturbation Growth in High-purity Copper Interface

作　　者：李碧勇 彭建祥[2] 谷岩[2] 尹晓春[1] 贺红亮[2] LI Biyong;PENG Jianxiang;GU Yan;YIN Xiaochun;HE Hongliang(School of Science, Nanjing University of Science and Technology,Nanjing 210094,Jiangsu,China;Institute of Fluid Physics,China Academy of Engineering Physics,Mianyang 621999,Sichuan,China)

机构地区：[1]南京理工大学理学院,江苏南京210094 [2]中国工程物理研究院流体物理研究所,四川绵阳621999

出　　处：《兵工学报》2020年第9期1809-1816,共8页Acta Armamentarii

基　　金：国家自然科学基金项目(11802287)。

摘　　要：为深入认识高压高应变率加载条件下影响金属界面Rayleigh-Taylor不稳定性扰动增长的相关因素及物理规律,以高纯铜为例开展金属界面扰动增长行为的数值模拟研究。基于有限差分程序AUTODYN建立爆轰加载下金属界面扰动增长的二维数值计算模型,重点分析界面初始扰动特征和材料强度特性对界面扰动增长行为的影响。相关数值模拟结果表明:高纯铜界面Rayleigh-Taylor不稳定性扰动增长与界面扰动的初始幅值和初始波长均密切相关,并存在一个临界幅值:在初始幅值小于临界幅值情况下,界面扰动的增长随初始波长增加而增大,最终趋于一个稳定值;当初始幅值大于临界幅值时,界面扰动的增长情况则相反。样品初始厚度对扰动幅值发展也起到重要作用,并存在一个临界厚度:在扰动增长初期,扰动幅值增长和纯流体模型的计算结果相似,几乎与材料强度无关;在扰动发展后期,材料屈服强度越大,相应地扰动幅值增长就越小。相比较而言,剪切模量对扰动幅值增长过程的影响可以忽略。The two-dimensional simulations of Rayleigh-Taylor instability perturbation growth of an initial perturbed copper interface under explosive loading are performed to study the Rayleigh-Taylor instability of metal interface under high pressure and high strain rate loading.A numerical simulation model for the perturbation growth behavior of metal interface is established based on the two-dimensional finite difference code AUTODYN,and the effects of initial perturbed characteristics and material strength property on the perturbation growth behavior of metal interface are mainly analyzed.The simulated results show that the growth of the pre-perturbed copper interface is closely related to its perturbated initial wavelength and amplitude,and a critical amplitude exists.For the stable case,the ultimate perturbation amplitude after a transient phase increases with the increase in the initial wavelength if the initial amplitude is smaller than the critical amplitude;and the growth behavior is opposite for the unstable case when the initial amplitude is larger than the critical amplitude.The initial thickness of plate is also an important factor for perturbation growth,and there is a critical thickness related to initial perturbation characteristics.In the preliminary stage of perturbation growth,the strength of material has no influence on the perturbation amplitude growth,and the yield strength of material can greatly reduce Rayleigh-Taylor growth rate at the later stage of Rayleigh-Taylor instability growth;and the effect of shear module can be neglectful to a certain extent in the period of perturbation growth.

关 键 词：高纯铜界面 RAYLEIGH-TAYLOR不稳定性 扰动增长 初始扰动特征 材料强度 数值模拟 

分 类 号：O389[理学—流体力学]