The agglomeration of particles during the handling of powders results in caking, lumping or the local accumulation of electrostatic energy which represents a serious hazard to the operational safety of industrial facilities. In the case of dry powders the attraction in-between particles can be mainly attributed to van der Waals and electrostatic forces. Nonetheless, due to the challenges related to the small size and distance of relevant particles and the optical density of powder flows the detailed physical mechanisms of their interaction are so far little investigated. In this paper we present a novel numerical approach which is based on an algorithm developed by Erleben [1] in the field of computer graphics. This algorithm is extended to compute binary and multiple particle interaction with each other and solid surfaces. Therein, besides van der Waals and electrostatic forces also collisional forces and plastic particle deformation is accounted for. The herein presented results demonstrate that this algorithm allows to predict accurately and efficiently whether particles agglomerate or separate depending on their kinetic parameters. In particular, the imposed constrain forces prevent spurious velocity fluctuations and potential particle overlapping in statically overdetermined systems. Simulated test cases reveal how electrostatic and van der Waals forces lead to the growth of structures in case the particle restitution coefficient is sufficiently low.

在粉末处理过程中，颗粒的团聚会导致结块，结块或局部积累的静电能，这对工业设施的操作安全构成了严重危害。对于干粉，颗粒之间的吸引力主要归因于范德华力和静电力。然而，由于与相关颗粒的小尺寸和距离以及粉末流的光密度有关的挑战，到目前为止，很少研究它们相互作用的详细物理机理。在本文中，我们提出了一种新颖的数值方法，该方法基于Erleben [1]在计算机图形学领域开发的算法。该算法被扩展为计算彼此之间和固体表面之间的二元和多重粒子相互作用。在里面 除了范德华力和静电力之外，还考虑了碰撞力和塑性颗粒变形。本文呈现的结果证明，该算法允许根据其动力学参数准确有效地预测颗粒是否团聚或分离。特别是，施加的约束力可防止在静态超定系统中出现伪速度波动和潜在的粒子重叠。模拟的测试案例揭示了在粒子复原系数足够低的情况下，静电力和范德华力如何导致结构的增长。本文呈现的结果证明，该算法允许根据其动力学参数准确有效地预测颗粒是否团聚或分离。特别是，施加的约束力可防止在静态超定系统中出现伪速度波动和潜在的粒子重叠。模拟的测试案例揭示了在粒子复原系数足够低的情况下，静电力和范德华力如何导致结构的增长。本文呈现的结果证明，该算法允许根据其动力学参数准确有效地预测颗粒是否团聚或分离。特别是，施加的约束力可防止在静态超定系统中出现伪速度波动和潜在的粒子重叠。模拟的测试案例揭示了在粒子复原系数足够低的情况下，静电力和范德华力如何导致结构的增长。