基于CG VOF-DEM和CG Mixture-DEM模型的水力旋流器多相流数值模拟

针对水力旋流器进料固体颗粒的分离过程内部流场复杂,颗粒运动规律难以掌握的问题。本文基于颗粒动力学理论并引入粗颗粒(CG)概念,提出了两种数值模型来对水力旋流器中的多相流进行建模：一种是将多相流(VOF)模型与离散元法(DEM)结合起来的CG VOF-DEM模型；另一种是将混合(Mixture)模型和DEM模型结合起来的CG Mixture-DEM。模拟结果表明,CG VOF-DEM模型在定量上适用于稀疏流,且仅定性地适用于稠密流。另一方面,CG Mixture-DEM模型可以定量地适用于稀疏流和稠密流。研究表明,CG Mixture- DEM模型可以作为评价水力旋流器分离性能的有效工具。

Numerical simulation of multiphase flow in hydrocyclone based on CG vof-dem and CG mixture DEM models

In order to solve the problem that the internal flow field is complex and the particle motion law is difficult to master in the separation process of solid particles fed by hydrocyclone. Based on the theory of particle dynamics and the concept of coarse particles (CG), two numerical models are proposed to model multiphase flow in hydrocyclones: one is CG vof-dem model which combines multi-phase flow (VOF) model with discrete element method (DEM); the other is CG mixture DEM which combines mixture model and DEM model. The simulation results show that the CG vof-dem model is suitable for sparse flow quantitatively and only qualitatively for dense flow. On the other hand, CG mixture DEM model can be applied to sparse flow and dense flow quantitatively. The results show that CG mixture DEM model can be used as an effective tool to evaluate the separation performance of hydrocyclones.