氩气在纳米孔内黏性系数变化规律的研究

The Argon's Viscosity Characteristics in Nanoporese

已有实验表明,气体在纳米孔内流动时其流动摩擦阻力系数远小于经典流体力学所给出的理论值。气体的黏性系数对其在纳米孔内流动时摩擦阻力大小起着重要作用,对其开展研究有助于理解气体在纳米尺度下表现出来的超流现象。本文采用分子动力学模拟方法对氩气在纳米孔内流动时的黏性系数进行研究。研究了氩气在纳米孔内表现出的平均黏性系数与纳米孔大小及气固间作用强弱的关系,及其随气体温度和压强的变化关系。对氩气黏性系数在纳米孔内的分布研究表明黏性系数在纳米孔内不为常数,而是表现出一定的分布规律,此现象为纳米孔内气体黏性系数与大空间下气体黏性系数最大的区别。本文的研究结果对人们理解气体在纳米孔内表现出超流现象有一定的帮助。

It has been shown by experiments that the gas＇ s flow rate is much larger than the classical fluid mechanic＇s prediction and its loss friction factor is much less than that predicted by the classical N-S equation.Gas viscosity plays an important role in determining gas flow loss friction factor and studies on gas viscosity are very helpful for people to understand the fast flow phenomenon in nanopores.Using molecular dynamics simulation the present paper studied the viscosity of argon gas when it is confined in nanopores.The mean viscosity of argon gas confined in nanopores and its change tendencies with the radius of nanopore,the interaction strength between the gas-solid,gas＇ s temperature and gas＇ s pressure are studied.Besides the mean gas viscosity,the profile of gas＇ s viscosity is also studied in the present paper.Our study results show that when argon gas is confined in nanopores its viscosity isn＇t one constant and shows certain change tendency which is the most important difference between the gas＇ s viscosity at macrospace and at nanopores.The study results by the present paper might bring lights on the understanding of fast flow phenomenon in nanopores.