论文标题
表面粒子运动通过低速正常影响激发的颗粒培养基激发
Surface particle motions excited by a low velocity normal impact into a granular medium
论文作者
论文摘要
在实验室实验中，高速视频用于检测和跟踪MM大小的表面粒子运动，这是由于低速效果对沙子的速度正常影响引起的。在最终的火山口半径之外，在弹射窗帘登陆之前，通过粒子跟踪速度法和互相关方法来测量粒子位移。表面颗粒反弹，也随着峰值和永久性位移的永久位移，随着距火山口中心距离的函数而迅速衰减。在大多数弹射窗帘降落之前，表面开始移动，但是在地下地震脉冲腐烂之后继续移动。表面和地下速度的射线角与Maxwell的Z模型所描述的速度相似。这意味着火山口开挖区域以外的流场是火山口发掘流的延续。最终颗粒位移与火山口半径的比率类似于其他撞击陨石坑的测量。
In laboratory experiments, high speed videos are used to detect and track mm-size surface particle motions caused by a low velocity normal impact into sand. Outside the final crater radius and prior to the landing of the ejecta curtain, particle displacements are measured via particle tracking velocimetry and with a cross-correlation method. Surface particles rebound and are also permanently displaced with both peak and permanent displacements rapidly decaying as a function of distance from the crater center. The surface begins to move before most of the ejecta curtain has landed, but continues to move after the subsurface seismic pulse has decayed. Ray angles for surface and subsurface velocities are similar to those described by a Maxwell's Z-model. This implies that the flow field outside the crater excavation region is a continuation of the crater excavation flow. The ratio of final particle displacement to crater radius resembles that measured for other impact craters.
