Mesoscopic Simulation of Binary Immiscible Fluids Flow in a Square Microchannel with Hydrophobic Surfaces
Mesoscopic Simulation of Binary Immiscible Fluids Flow in a Square Microchannel with Hydrophobic Surfaces
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DOI：
10.3970/cmes.2007.019.181
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发表时间：
2007-06
影响因子：
2.4
通讯作者：
S. Chen;Yang Liu;B. Khoo;X. J. Fan;J. Fan
中科院分区：
文献类型：
--
作者：
S. Chen;Yang Liu;B. Khoo;X. J. Fan;J. Fan
采用耗散粒子动力学方法对方形微通道内流体流动进行了细观模拟。将计算得到的方形通道内单股流体的速度分布与CFD求解器的解进行了比较，两者吻合较好。当排斥系数在9.68~18.0之间时，无滑移边界条件能很好地满足。在相同的排斥系数范围内，通过改变排斥系数可以得到不同的润湿性，其中不互溶流体是通过增加物种间的排斥力来实现的。DPD粒子的典型运动可以描述为布朗运动，这与MD模拟结果相似。DPD模拟的液/液界面张力与理论预测值雅阁。对于相同的排斥参数，流体/固体界面张力总是大于流体/流体界面张力。DPD模拟的静态接触角与Young方程吻合较好，尽管由于热波动而存在一些差异。对于动接触线，前进和后退接触角是不同的。结果表明，疏水流体的截面积向方形微通道的中心部分收缩，形成一个圆形截面。1香港理工大学机械工程系，香港九龙红磡;中国，200030 3通讯作者。电子邮件：www.example.com 4工程系统的高性能计算，新加坡-麻省理工学院联盟，新加坡国立大学，新加坡117576 5聚合物合作研究中心，32 Business Park Drive诺丁山，维克3168，澳大利亚6香港理工大学纺织与服装学院，香港九龙红磡。疏水流体的收缩程度取决于速度本身。对于不互溶流体，增大流体A与壁面之间的排斥系数可以提高流体A在微通道内的运动速度，且静态角越大，运动速度越大。关键词：耗散粒子动力学;微通道;不互溶二元流体
The mesoscopic simulation for fluids flow in a square microchannel is investigated using dissipative particle dynamics. The velocity distribution for single fluid in a square channel is compared with the solutions of CFD solver, which is found to be in good agreement with each other. The no-slip boundary condition could be well held for the repulsive coefficient ranged from 9.68 to 18.0. For the same range of repulsive coefficient, various wettabilities could be obtained by changing the repulsive coefficient for binary immiscible fluids, in which the immiscible fluids are achieved by increasing the repulsive force between species. The typical motion of the DPD particle might be described as Brownian, which is similar to MD simulation results. The DPD simulated fluid/fluid interfacial tension is in accord with theoretical prediction. For the same repulsive parameters, the fluid/solid interfacial tension is always greater than the fluid/fluid interfacial tension. The DPD simulated static contact angles are in good agreement with Young’s equation even though some differences exist due to thermal fluctuation. For moving contact line, the advancing and receding contact angles are different with each other. It is found that the cross-section area of hydrophobic fluid retracts towards the central part of the square microchannel and forms a cir1 Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong 2 School of Mechanical and Power Engineering, Shanghai Jiaotong University, Shanghai, P. R. China, 200030 3 Corresponding author. E-mail: mmyliu@polyu.edu.hk 4 High Performance Computation for Engineered System, Singapore-MIT Alliance, National University of Singapore, Singapore 117576 5 Cooperative Research Centre for Polymers, 32 Business Park Drive Notting Hill, VIC 3168, Australia 6 Institute of Textile and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong cle. The retraction extent of the hydrophobic fluid is dependant on the velocity itself. For immiscible fluid, the moving velocities of fluid A in a microchannel could be increased by increasing the repulsive coefficient between fluid A and walls, and larger static angle may produce larger moving velocity. Keyword: Dissipative particle dynamics; Microchannel; Immiscible binary fluids