摘要
Energy dissipation is one of the most important properties of granular gas, which makes Its behavior dltterent trom that of molecular gas. In this work we report our investigations on the freely-cooling evolution of granular gas under microgravity in a drop tower experiment, and also conduct the molecular dynamics （MD） simulation for comparison. While our experimental and simulation results support Haff＇s law that the kinetic energy dissipates with time t as E（t） （1 ＋ t/v） 2, we modify ~＂ by taking into account the friction dissipation during collisions, and study the effects of number density and particle size on the collision frequency. From the standard deviation of the measured velocity distributions we also verify the energy dissipation law, which is in agreement with Haff＇s kinetic energy dissipation.
Energy dissipation is one of the most important properties of granular gas, which makes Its behavior dltterent trom that of molecular gas. In this work we report our investigations on the freely-cooling evolution of granular gas under microgravity in a drop tower experiment, and also conduct the molecular dynamics （MD） simulation for comparison. While our experimental and simulation results support Haff＇s law that the kinetic energy dissipates with time t as E（t） （1 ＋ t/v） 2, we modify ~＂ by taking into account the friction dissipation during collisions, and study the effects of number density and particle size on the collision frequency. From the standard deviation of the measured velocity distributions we also verify the energy dissipation law, which is in agreement with Haff＇s kinetic energy dissipation.
作者
王文广
厚美瑛
陈科
虞培东
Matthias Sperl
Wen-Guang Wang;Mei-Ying Hotl;Ke Chen;Pei-Dong Yu;Matthias Sperl(Key Laboratory of Soft Matter Physics,Beijing National Laboratory for Condensed Matter Physics,Institute of Physics Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Institut fr Materialphysik im Weltraum,Deutsches Zentrum fiir Luft-und Raumfahrt,KOln 51170,Germany)
基金
Project supported by the National Natural Science Foundation of China(Grant Nos.U1738120 and 11474326)
