静电力对微米颗粒团稳定性影响的数值模拟

Numerical Simulation on the Effects of Electrostatic Force on the Stability of Agglomerates Formed by Microparticles

在静电除尘器等工业设备中,静电相互作用普遍存在并显著影响微米颗粒的动力学行为。在静电计算中,常用的点电荷模型在颗粒互相靠近后不再适用,导致预测颗粒运动时出现偏差。因此,本文采用边界元法精确求解荷电颗粒间的静电力,并基于边界元-离散动力学耦合方法模拟单颗粒与荷电颗粒团的碰撞过程,进而讨论静电力对颗粒团聚的影响机制。研究发现,颗粒表面诱导电荷能够增强荷电颗粒团稳定性。同时,在静电力驱动下,颗粒团结构在碰撞后不断动态演变,保持较为疏松的结构。

In industrial devices such as the electrostatic precipitator, the electrostatic interaction widely exists and significantly affects the dynamic behavior of microparticles. The commonly used point-charge model in the electrostatic calculation is no longer valid if particles are close to each other, leading to deviations when predicting particle motions. Therefore, the boundary element method is employed to accurately account for the electrostatic force between charged particles in the present study. The boundary element method-discrete element method coupled approach is applied to simulate the collision between a single particle and a charged agglomerate, based on which the influence of the electrostatic force on particle agglomeration is discussed. It is revealed that, the induced surface charge could enhance the stability of the charged agglomerate. Moreover, driven by the electrostatic force, the agglomerate undergoes dynamic structural evolutions after the collision while retaining a relatively loose structure.