论文标题
通过连续的影响穿透颗粒介质
Penetrating a granular medium by successive impacts
论文作者
论文摘要
我们考虑垂直圆柱体的穿透动力学到受到连续影响的干颗粒培养基中。自由表面$ z_n $以下影响器的深度首先与撞击数$ n $线性演变，然后遵循幂律进化$ z_n \ propto n^{1/3} $。观察到给定数量的撞击后，气缸到达的深度随着冲击能量的增加而增加，但随着其直径和颗粒介质的密度而降低。我们开发了一个模型，该模型解释了应用于圆柱体上的准静态和惯性颗粒力，以合理化我们的观察结果。这种方法揭示了对大小影响数字的两个入侵制度的存在，从而使所有数据都可以在主曲线上重新缩放。然后，我们将研究扩展到侧壁对影响器动力学的影响。我们表明，横向限制改变了影响器深度对撞击数$ z_n（n）$的依赖性。通过考虑横向限制的颗粒阻力增加来解释这种效果。
We consider the penetration dynamics of a vertical cylinder into a dry granular medium subjected to successive impacts. The depth of the impactor below the free surface $z_N$ first evolves linearly with the impact number $N$ and then follows a power-law evolution $z_N \propto N^{1/3}$. The depth reached by the cylinder after a given number of impacts is observed to increase with the impact energy but to decrease with its diameter and the density of the granular medium. We develop a model that accounts for the quasi-static and inertial granular forces applying on the cylinder to rationalize our observations. This approach reveals the existence of two intrusion regimes for large and small impact numbers, allowing all data to be rescaled on a master curve. Then, we extend the study to the effect of sidewalls on the dynamics of the impactor. We show that lateral confinement changes the dependence of the impactor depth on the impact number $z_N (N)$. This effect is accounted for by considering the increase of the granular drag with the lateral confinement.
