物理学报Issue(1)：014502-1-014502-7,7.DOI:10.7498/aps.65.014502
颗粒气体团簇行为实验研究∗
Exp erimental study of clustering b ehaviors in granular gases
摘要
Abstract
Granular materials are widely spread in nature and in industry. Owing to the inelastic collisions between particles and frictions among particles, granular systems are dissipative in nature. This intrinsic dissipative nature causes local clustering in granular gas systems. This is a unique phenomenon compared with the molecular gases. Understanding and predicting the condition and parameter values when this phenomenon happens will be helpful for us to gain knowledge of the conditions of clustering or pattern formations in non-equilibrium complex systems. The clustering phenomenon in granular gas is analyzed using phase-separation modeling of van der Waals-like molecules. The results from the model are verified by molecular dynamics numerical simulations. However, due to the influence of the gravity, experimental verification is difficult in laboratory. In this work, we perform an experiment in micro-gravity environment provided by the drop tower of National Microgravity Laboratory Chinese Academy of Science. In the experiment we for the first time observe the phase-separation clustering phenomenon. Comparing the observation condition with the model prediction, we are able to indirectly obtain the restitution coefficients of particles used in the experiment. A model calculation for the spinodal regime under experimental conditions is performed for possible particle restitution coefficients, and a comparison with the experimental observation allows us to justify the values of the restitution coefficients. It is found that the coefficient is larger for bigger particles. For d=2.5 mm titanium particles, the restitution coefficient is higher than 0.8; for d=1 mm titanium particles, the restitution coefficient is about 0.8, and for d=0.5 mm titanium particles, the restitution coefficient is between 0.6 and 0.8. This useful result can be essential for comparing experimental observation with the theoretical and the numerical results, and is crucial to the success in the SJ-10 satellite experiments.关键词
颗粒气体/微重力/团簇/落塔Key words
granular gases/low-gravity/cluster/drop tower引用本文复制引用
王花,陈琼,王文广,厚美瑛..颗粒气体团簇行为实验研究∗[J].物理学报,2016,(1):014502-1-014502-7,7.基金项目
中国科学院空间科学战略性先导科技专项(批准号：XDA04020200)、国家自然科学基金(批准号:11274354,11474326)和地震行业科研经费(批准号:201208011)资助的课题.* Project supported by the “Strategic Priority Research Program-SJ-10” of the Chinese Academy of Sciences (Grant No. XDA04020200), the National Natural Science Foundation of China (Grant Nos.11274354,11474326), and the Special Fund for Earthquake Research of China (Grant No.201208011) （批准号：XDA04020200）
