The divergence of nearby trajectories in soft-sphere DEM  

作　　者：William D.Fullmer Roberto Porcu Jordan Musser Ann S.Almgren Ishan Srivastava 

机构地区：[1]National Energy Technology Laboratory,Morgantown,WV 26507,USA [2]NETL Support Contractor,Morgantown,WV 26507,USA [3]Center for Computational Sciences and Engineering.Lawrence Berkeley National Laboratory,Berkeley,CA 94720,USA

出　　处：《Particuology》2022年第4期1-8,共8页颗粒学报（英文版）

摘　　要：The n-body instability is investigated with the soft-sphere discrete element method.The divergence of nearby trajectories is quantifed by the dynamical memory time.Using the inverse proportionality between the dynamical memory time and the largest Lyapunov exponent,the soft-sphere discrete ele-ment method results are compared to previous hard-sphere molecular dynamics data for the first time.Good agreement is observed at low concentrations and the degree of instability is shown to increase asymptotically with increasing spring sifness.At particle concentrations above 30%,the soft-sphere Lya-punov exponents increase faster than the corresponding hard-sphere data.This paper concludes with a demonstration of how this case study may be used in conjunction with regression testing and code verification activities.

关 键 词：Soft-sphere DEM CHAOS Lyapunov exponent 

分 类 号：O17[理学—数学]