胶体微泵的耗散粒子动力学模拟

Numerical Simulation of a Colloidal Micropump by Dissipative Particle Dynamics

应用耗散粒子动力学方法研究了胶体微泵.每个胶体小球按照既定的运动规律相继运动,从而可驱动流体.首先利用耗散粒子动力学方法计算了泊肃叶流动,验证了模拟的正确性.然后模拟了由六个胶体小球组成的周期性胶体微泵的工作过程.胶体颗粒与周围流体粒子之间采用了弹性碰撞模型;模拟中选择了合适的参数,从而可提高流体的粘度并保证DPD流体的不可压缩性.模拟结果与他人的实验数据进行了对比,两者很好吻合.模拟结果显示,胶体微泵的无量纲流量的绝对值随着小球运动ω的变小而增大;而随着ω的减小,无量纲流量的振幅也相应变大.

The colloidal micropump was investigated by using dissipative particle dynamics. The colloidal bodies move with a prescribed law and have the ability of driving the surrounding fluid. Firstly, the Poiseuille flow was simulated by DPD, validating the accuracy of this method. Then the working process of the periodic mcropump with 6 colloidal bodies was simulated. An elastic collision model between the moving bodies and the DPD fluid particles was employed. Appropriate parameters were selected in order to increase the viscosity and to ignore the compressibility effects of the DPD fluid. It was found that the simulated results of the colloidal micropurnp are in good agreement with the experimental results. The results also shows that the dimensionless flow rate and the amplitude of the transverse oscillations increased with the decreasing of ω.