颗粒气体团簇行为实验研究

发布时间：2018-03-27 04:53

本文选题：颗粒气体　切入点：微重力　出处：《物理学报》2016年01期

【摘要】：颗粒体系由于非弹性碰撞和摩擦等内秉的能量耗散特性,由宏观粒子形成的颗粒气体体系经常会有局部凝聚现象,这是颗粒气体体系与分子气体体系的最大区别之一.理解和预测这一现象的发生将有助于人们对远离平衡态体系的复杂现象,如有序结构、斑图和团簇形成的认知.这种局部凝聚现象可以类比于分子气体中亚稳分解形成的液滴,将气液相分离用于解释和寻求局部凝聚现象的此模型得到了分子动力学模拟的校验.但是实验的校验却由于宏观粒子运动受重力作用的影响难以在实验室中实现.作为实践十号卫星的前期实验,本文利用国家微重力实验室落塔装置,以水平激振装有不同尺寸和数目的颗粒样品,在短时微重力条件下,成功观察到颗粒气体团簇的形成;并将实验结果与颗粒气体类范德瓦耳斯气体分子相分离模型对比,由形成团簇样品的颗粒数密度条件,来实验确定了所选颗粒的恢复系数,得到直径为0.5 mm的钛珠颗粒的恢复系数在0.6—0.8之间,直径为1 mm的钛珠颗粒的恢复系数约为0.8,直径为2.5 mm的钛珠颗粒的恢复系数应大于0.8.
[Abstract]:Due to the energy dissipation characteristics of inelastic collision and friction, particle gas systems formed by macroscopic particles often exhibit local condensation. This is one of the biggest differences between a granular gas system and a molecular gas system. Understanding and predicting the occurrence of this phenomenon will contribute to the understanding of complex phenomena far from equilibrium systems, such as ordered structures, Pattern and cluster formation. This phenomenon of local condensation can be analogous to the formation of droplets formed by the metastable decomposition of molecular gases. The model of gas-liquid phase separation is used to explain and seek local condensation phenomenon. The verification of molecular dynamics simulation is obtained, but the verification of experiment is difficult to be realized in the laboratory because of the effect of gravity on the macroscopic particle motion. As a preliminary experiment in the practice of satellite 10, In this paper, the formation of granular gas clusters has been successfully observed under the condition of short-term microgravity by using the tower dropping device of the National Microgravity Laboratory and the horizontal excitation with different size and number of particle samples. The experimental results are compared with the van der Waals gas molecular separation model, and the recovery coefficient of the selected particles is determined by the particle number density condition of the cluster sample. The recovery coefficient of titanium beads with diameter of 0.5 mm is between 0.6-0.8, and that of titanium beads with diameter of 1 mm is about 0.8. The recovery coefficient of titanium beads with diameter of 2.5 mm should be greater than 0.8.
【作者单位】：北京理工大学物理学院;中国科学院物理研究所软物质物理重点实验室北京凝聚态物理国家实验室;
【基金】：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) 地震行业科研经费(批准号:201208011)资助的课题~~
【分类号】：O347.7

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