基于郎之万方程和LBM的Janus颗粒自驱运动模拟  

Simulation of Janus particles self-driven motion based on Langevin equation and LBM

作　　者：张焱[1] 崔海航[1] 周敏[2] 陈力[1] 

机构地区：[1]西安建筑科技大学环境与市政工程学院,西安710055 [2]中国地质调查局西安地质调查中心,西安710054

出　　处：《水动力学研究与进展（A辑）》2017年第2期237-246,共10页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金项目(11447133);陕西省教育厅专项科研计划(15JK1385)~~

摘　　要：Janus颗粒由于本身的自驱动特性在生物能源医药等领域具有广阔的应用前景,然而其自驱动特性研究目前还不完善。该文基于格子Boltzmann方法(LBM)和郎之万方程,结合反弹边界格式建立了模拟球形Janus颗粒自驱动的动力学模型,利用爱因斯坦关系式对运动方程中的布朗力进行修正,相对于涨落LBM大幅降低了计算量,提高了计算效率。通过模拟2μm球形Janus颗粒的自驱运动并与实验结果对比得出,采用该方法模拟所得颗粒运动特性与实验相符,验证了该方法的可行性与准确性。通过在特定情况下扩散系数与扩散泳力的关系图与实验结果的对比,可得出不同燃料浓度作用下Janus颗粒受到扩散泳力的大小,为后续实验和数值模拟工作的展开提供了有力的支撑。Janus particles due to its self-driven feature have a major prospect in bioenergy, medicine, energy and other fields, however, the research of self-driven feature is not yet perfect. Based on Lattice Boltzmann Method （LBM） and Langevin equation, a dynamic model to simulate spherical Janus particles self-driven was built combined with link-bounce-back boundarycondition, and the Brown force in motion equation was corrected by the Einstein relationship. Compared with fluctuating LBM, the amount of calculation was dramatically reduced and the computational efficiency was improved. By simulating 2 grn spheri- cal Janus particles self-propelled movement and compared with the experimental results, the simulation result of the particle motion using this method was consistent with experimental result, which verified the feasibility and accuracy of the method. By comparing the diffusion coefficient and diffusiophoresis force diagram with the experimental results under certain circumstances, the diffusiophoresis force sizes of Janus particles for different concentrations fuel were obtained. The work provided a strong support for subsequent experiments and numerical work of Janus particles.

关 键 词：布朗运动 格子BOLTZMANN方法 Janus粒子 自驱动 

分 类 号：O35[理学—流体力学]