Surface deformation and rebound for normal single-particle collisions in a surrounding fluid
Surface deformation and rebound for normal single-particle collisions in a surrounding fluid
复制标题
DOI：
10.1017/jfm.2019.349
复制
发表时间：
2019-06
影响因子：
3.7
通讯作者：
A. Ruiz‐Angulo;S. Roshankhah;M. Hunt
中科院分区：
文献类型：
--
作者：
A. Ruiz‐Angulo;S. Roshankhah;M. Hunt
本文介绍了实验测量，涉及刚性冲击器和可变形的目标之间的浸没碰撞的雷诺数和斯托克斯数的范围很广。三种铝合金被用作浸没在七种不同的流体中的固体靶，覆盖了广泛的粘度和密度。高分辨率地测量了碰撞和反弹速度以及碰撞产生的弹坑的深度和直径。在这项研究中的大多数实验发生在速度的变形是在弹塑性制度。用弹性、塑性和弹塑性理论对空气中的实验结果进行了分析，说明了弹塑性碰撞模型的复杂性。对于在液体中的碰撞，测量表明，弹坑的大小是独立的流体特性，如果斯托克斯数是超过一个临界值。恢复的正常系数可以估计包括粘性损失和塑性效应，并假设碰撞时间尺度是显着短于流体动力学时间尺度。的弹坑尺寸的结果也被用来开发的材料的变形量作为材料的性能和影响和临界斯托克斯数的函数的分析表达式。
This article presents experimental measurements involving immersed collisions between a rigid impactor and a deformable target for a wide range of Reynolds and Stokes numbers. Three aluminium alloys are used as solid targets submerged in seven different fluids covering a wide range of viscosity and density. The collision and rebound velocities as well as the depth and diameter of the crater produced by the collisions are measured with high resolution. Most of the experiments in this study occur at velocities for which the deformation is within the elastic–plastic regime. Results of the experiments in air are analysed by elastic, plastic and elastic–plastic theories, and demonstrate the complexities of modelling elastic–plastic collisions. For collisions in a liquid, the measurements show that the size of the crater is independent of the fluid characteristics if the Stokes number is beyond a critical value. The normal coefficient of restitution can be estimated by including both viscous losses and plasticity effects and assuming that the collision time scale is significantly shorter than the hydrodynamic time scale. The results of the crater dimensions are also used to develop an analytical expression for the volume of deformation of the material as a function of material properties and the impact and critical Stokes numbers.