Guo Chengcheng, Li Lei, Chen Han, Zhang Ruizhi, Bai Jinsong, Shen Qiang, Zhang Lianmeng, Luo Guoqiang
State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China.
Heliyon. 2023 Feb 18;9(3):e13704. doi: 10.1016/j.heliyon.2023.e13704. eCollection 2023 Mar.
Hypervelocity impact in the universe can be generated by a three-stage gas gun. Achieving the desirable planarity of the flyer enlarges the experimentally effective area of the flyer under the hypervelocity condition. The multidimensional graded density impactor (MDGDI) enhances the planarity of the flyer. In this investigation, a one-dimensional Lagrange elastoplastic hydrodynamic method and a Euler grid finite difference method were used to examine the relationship between the structure of graded density impactors (GDIs) and the planarity of flyers. MDGDIs lead to a deviation of the stress wave produced by the one-dimensional graded density impactor (1DGDI), which offsets the stress disturbance effect, changes the velocity at each particle, and enhances the planarity of flyers. The proportion of flat areas of the flyer increases from 52.70% to 95.71% by adopting MDGDIs. The proportion of flat areas is linear with the wave impedance of the high-impedance layer for 1DGDIs and the wave impedance near the barrel of the high-impedance layer for MDGDIs. This investigation guides the design of GDIs and expands the application of gas gun technology in the field of hypervelocity impact.
宇宙中的超高速撞击可由三级气炮产生。实现飞片所需的平整度可扩大超高速条件下飞片的实验有效面积。多维梯度密度撞击器（MDGDI）可提高飞片的平整度。在本研究中，采用一维拉格朗日弹塑性流体动力学方法和欧拉网格有限差分法来研究梯度密度撞击器（GDI）的结构与飞片平整度之间的关系。MDGDI会导致一维梯度密度撞击器（1DGDI）产生的应力波发生偏差，抵消应力扰动效应，改变每个粒子的速度，并提高飞片的平整度。采用MDGDI后，飞片平坦区域的比例从52.70%增加到95.71%。对于1DGDIs，平坦区域的比例与高阻抗层的波阻抗呈线性关系；对于MDGDIs，平坦区域的比例与高阻抗层炮管附近的波阻抗呈线性关系。本研究为GDI的设计提供了指导，并拓展了气炮技术在超高速撞击领域的应用。
