冲击加载锡表面喷出物云的质量-速度和尺寸-速度分布的原子模拟
Mass-velocity and size-velocity distributions of ejecta cloud from shock-loaded tin surface using atomistic simulations
摘要：
采用大尺度分子动力学（MD）模拟研究了激波诱导粒子云的质量（体积密度和面密度）与速度的关系以及粒子云的尺寸与速度的关系。将具有正弦自由表面粗糙度（单波长）的通用3D锡晶体设置为与真空接触并加载冲击，使得其在冲击时直接熔化。在冲击波反射到自由表面的扰动上时，喷射液态金属的2D片/射流。模拟结果表明，该分布可以描述的分析模型的基础上的一个破碎区的传播，从尖端的片材的自由表面，在其中的原子的动能减少，因为这个区域来更接近自由表面上晚的时间。由于该动能驱动（i）一旦区域从片材脱离，区域的（自相似）膨胀和（ii）由区域中的破碎产生的颗粒的平均尺寸，随着破碎发生在更靠近自由表面处，喷射的质量和颗粒的平均尺寸在云中逐渐增加。虽然相对于纳米尺度，我们的模型再现定量实验配置文件，并可能有助于他们的分析。
英文摘要：
The mass (volume and areal densities) versus velocity as well as the size versus velocity distributions of a shock-induced cloud of particles are investigated using large scale molecular dynamics (MD) simulations. A generic 3D tin crystal with a sinusoidal free surface roughness (single wavelength) is set in contact with vacuum and shock-loaded so that it melts directly on shock. At the reflection of the shock wave onto the perturbations of the free surface, 2D sheets/jets of liquid metal are ejected. The simulations show that the distributions may be described by an analytical model based on the propagation of a fragmentation zone, from the tip of the sheets to the free surface, within which the kinetic energy of the atoms decreases as this zone comes closer to the free surface on late times. As this kinetic energy drives (i) the (self-similar) expansion of the zone once it has broken away from the sheet and (ii) the average size of the particles which result from fragmentation in the zone, the ejected mass and the average size of the particles progressively increase in the cloud as fragmentation occurs closer to the free surface. Though relative to nanometric scales, our model reproduces quantitatively experimental profiles and may help in their analysis.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
