A discrete-element method is presented for efficient computational modeling of the transport, collision and adhesion of small particles immersed in a fluid flow. Adhesive particles are of major concern for a wide variety of engineering systems, including particle separation and mixing processes in microfluidic sensors, clogging of heat exchanger channels on construction equipment, soot formation from combustion processes, solid rocket fuel processing, platelet activation in blood flow through artificial valves, entrainment and transport of cohesive sediments, cement manufacture, and nanoparticle fabrication, processing, and dispersion processes. The discrete-element method presented in this talk is developed to enable efficient prediction of aggregate structure and breakup, for prediction of the effect of aggregate formation on the bulk fluid flow, and for prediction of the effects of small-scale flow features (e.g., due to surface roughness or lithographic patterning) on the aggregate formation. We particularly focus on computations with non-spherical particles (e.g., for blood flow) and with particle transport in complex domains. Also considered are problems involving capture of particle aggregates by the system walls, which cannot be predicted with the more standard continuum aggregation formulations based on the Smoluchowski equation. An overview of the computational structure and modeling assumptions is presented, including models for various forces and torques used to model particle-particle collisions. Three different particle adhesion forces will be discussed, including van der Waals adhesion, liquid-bridging adhesion, and ligand-receptor binding of biological cells. The method is then demonstrated for a variety of physical problems in engineering and biology. 

流体流动中细颗粒传输、碰撞和粘附的高效离散元模拟：

        颗粒团聚物的结构和破碎；细尺度流动对团聚物形成的影响；壁面对团聚物的捕获；特别关注非球形颗粒及复杂流域颗粒传输的模拟；

        数值计算结构及模型假设，包括碰撞中力和力矩的计算模型；考虑颗粒间粘附力：范德华力、液桥力以及生物细胞间的配体-受体结合

        离散元颗粒动力学模拟在一系列工程(环境、能源和化学工程)以及生物学等研究中未来具有广泛上的前景。