纤维集合体对PM_(2.5)过滤特性的数值模拟

Numerical Simulation on PM_(2.5) Filtering by Fibrous Assembly

本文基于对气相场的分析以及颗粒运动轨迹的计算,结合AutoCAD中的Lisp程序以及前处理软件Gambit,建立三维纤维集合体过滤介质模型来研究纤维介质对气溶胶颗粒的捕集效率。利用计算流体力学(CFD)对纤维间气固两相流动特性进行数值模拟研究,用欧拉法处理气相场的同时用拉格朗日方法处理离散颗粒场,探究不同线密度(ρ)、不同孔隙率(e)下纤维集合体对PM_(2.5)的捕集特性。结果表明:对于同一种丝束,纤维集合体的捕集效率随着孔隙率的增加而减小。在相同的孔隙率下,纤维集合体的捕集效率随着纤维线密度的增大而减少。

According to the analysis of flow field and the calculations of particle trajectory,we combined the Lisp program language in AutoCAD with preprocessing software Gambit to generate a series of 3-D fibrous assembly filtering models,which were used to research the collection efficiency of fibrous assembly media when challenged with aerosol particles.Computational fluid dynamics(CFD)methods were adopted to simulate the features of the gas-solid two phase flow between the fibers.We used Lagrangian methods to solve flow field and Eulerian methods to solve discrete particle field,respectively.The collection characteristics on PM2.5 filtering by fibrous assembly would be studied considering different factors such as voidages(ε) and linear densities(ρ).The results show that at the same circumference,the particulate matter collection efficiency reduces as the voidage increases.We also find that with a certain voidage,the particulate matter collection efficiency reduces as the linear density increases.