摘要
基于浸没边界-格子Boltzmann方法,对方形截面微通道内椭球颗粒的惯性迁移与旋转动力学行为进行数值研究,发现微通道内椭球颗粒的惯性迁移存在两种主要的运动状态:①翻转状态,即椭球颗粒前进过程中长轴始终在中心对称平面内;②滚动状态,即椭球颗粒前进过程中长轴始终垂直于中心对称平面.研究表明:在低Re数(Re=10)下颗粒以两种状态随流体迁移至平衡位置;在较大Re数(50≤Re≤200)下最终均以翻转状态随流体迁移,随Re数增加,平衡位置先逼近壁面后远离壁面.通过对不同运动状态下椭球颗粒周围的微观流场进行分析,提示该微观流动在颗粒惯性聚焦行为特征中有重要影响,并从流体和颗粒的惯性角度对颗粒不同运动状态的转换机理给出解释.
With immersed boundary-lattice Boltzmann method,inertial migration behavior and rotational dynamics of an ellipsoidal particle in an infinite square cross-section microchannel were numerically studied.Two main motion states were found for ellipsoidal particles migrating in a microchannel,i.e.,tumbling and log-rolling.It shows that for particles in flow with relatively low Re(Re=10),rotational behavior varied from different initial orientation.However,for particles in flow with higher Re(50≤Re≤200),they perform same rotational behavior and reach the same equilibrium position.As Re number increases,equilibrium position of the ellipsoidal particle moves firstly towards the wall then the center of the channel.At higher Re numbers(Re>300),the particles do not retain stable inertial focusing.Finally,the phenomena were analyzed from flow field around the particles.In addition,mechanism of transition of motion states of particles is explained from fluid and particle inertia.
作者
王坚毅
潘振海
吴慧英
WANG Jianyi;PAN Zhenhai;WU Huiying(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《计算物理》
CSCD
北大核心
2020年第6期677-686,共10页
Chinese Journal of Computational Physics
基金
国家自然科学基金(51536005,51820105009,51706136)资助项目。
