中文摘要：

以低表面能纳米通道内液态Poiseuille流为对象,采用分子动力学模拟方法研究通道壁面上布置二级规则微结构后对微流动特性的影响规律.数值模拟中,统计系综为微正则系综,势能函数采用L J/126模型,壁面定义为Rigid-atom壁面,温度校正使用速度定标法,而壁面低表面能属性则通过调整壁面铂原子与液态氩原子间的势能参数来实现.结果表明,布置二级矩形和三角形微结构后壁面附近流体密度法向分布会出现两个振荡阶段,即在微结构内部出现振幅相对较小的次级振荡过程,但通道中心区流动与光滑壁面通道相似;随微结构周期T的增大,二级微结构内密度法向振幅逐渐增大,而近壁面区域振幅则减弱;而二级微结构深度H的增大,则导致其内的次级振荡幅值减小,且分布起点随之下移.另外,随微结构周期T、深度H的增大,通道内流体平均流量均逐渐增大,即呈现更好的减阻效果.

英文摘要：

In order to investigate the property of nano-Poiseuille flow using molecular dynamics simulation,while the channel has secondary regular microstructure and low surface energy.In the simulation,statistical ensemble is set as NVE,LJ/126 model as the potential energy function and rigid-atom model is used to describe the wall and the time/rescale thermostat to keep the temperature of fluid constant.Meanwhile,the potential energy parameter between solid and liquid atoms is adjusted to realize the wall of low surface energy.The results show that when the channel wall has microstructure,the vertical density profiles of fluid appeared two oscillation regions near the wall,namely significant weak oscillation within the microstructure（called second oscillation） and strong oscillation in the channel.With the increase of rectangle microstructure period （T）,the oscillation degree of density profile within the secondary microstructure increase,while the oscillation in the channel is decrease.The increase of depth （H） of the rectangle microstructure result in a secondary oscillation amplitude decreases and the starting point of density profile move away the center of channel.The period and depth of the secondary microstructure also has a significant influence on the flow.As T and H increase,the average flux of channel also increase,which suggests that the channels present better drag reduction effect.