初速度对运动物体在颗粒介质中阻力的影响  

Effects of the Initial Velocity on the Drag Force of a Projectile in Granular Medium

作　　者：叶见兰[1] 杨先清[1] 郭海萍[1] 陈琼[1] 王振辉[1] 

机构地区：[1]中国矿业大学理学院,江苏徐州221008

出　　处：《宁波大学学报（理工版）》2011年第1期58-62,共5页Journal of Ningbo University：Natural Science and Engineering Edition

基　　金：国家自然科学基金创新研究群体科学基金(50921002)

摘　　要：采用分子动力学模拟方法研究物体从二维颗粒介质底部上升过程的动力学行为.研究发现,物体在上升过程中所受到的阻力与物体的初速度有关.当物体的初速度较小时,黏性系数随着初速度增加而减小,等效阻力则逐渐增加;而当初速较大时,黏性系数随着初速度增加反而逐渐增加,而等效阻力则逐渐减少,甚至可转变成等效推力.We study the dynamic behavior of a projectile going up from the bottom of a two-dimensional granular medium by molecular dynamic simulations. We find that the drag force of the projectile in the rising process can be well described by adding a viscous damping and a bulk frictional force. The viscous coefficient decreases with the increase of initial velocity, but the bulk frictional force gradually increases when the initial velocity is small. However, when the initial velocity is large, with the increasing of it, the viscous coefficient increases, but the bulk frictional force gradually decreases, even transforms into an equivalent thrust force.

关 键 词：颗粒介质 分子动力学 黏性阻力 等效阻力 

分 类 号：O414.22[理学—理论物理]