椭圆纤维过滤压降与惯性捕集效率数值分析  

Numerical analysis of filtration pressure drop and inertial collection efficiency for elliptical fibers

作　　者：朱辉[1,2] 杨会[1] 付海明[1] 亢燕铭[1] ZHU Hui;YANG Hui;FU Hai-ming;KANG Yan-ming(School of Environmental Science and Engineering,Donghua University,Shanghai 201620,China;School of Energy and Building Environment,Guilin University of Aerospace Technology,Guilin 541004,China)

机构地区：[1]东华大学环境科学与工程学院,上海201620 [2]桂林航天工业学院能源与建筑环境学院,广西桂林541004

出　　处：《中国环境科学》2019年第2期565-573,共9页China Environmental Science

基　　金：国家自然科学基金资助项目(51178094);广西自然科学基金资助项目(2017GXNSFAA198184)

摘　　要：采用数值方法求解了描述椭圆截面纤维绕流特征的Navier-Stokes方程,并计算了椭圆纤维对粒子惯性捕集效率及纤维过滤压降.分析讨论了椭圆纤维迎风角度θ、长短轴比ε和填充率C等参数对惯性粒子过滤性能的影响.结果表明,在大迎风角度时,过滤压降随长短轴比增大而增大,而在小迎风角度下,过滤压降则随长短轴比增大而减小;在相同纤维长短轴比条件下,过滤压降均随迎风角增大而增加.粒子惯性捕集效率计算结果则表明,对于中高惯性粒子捕集,大迎风角度和高长短轴比的椭圆纤维的捕集效率高于圆截面纤维,而对弱惯性粒子,小迎风角度和高长短轴比的椭圆纤维则表现出较高的捕集效率.在椭圆纤维过滤压降和捕集效率计算基础上,采用纤维过滤质量因子(定义为捕集效率比过滤阻力)评价综合过滤性能.结果表明,对于中高惯性粒子过滤,扁长型椭圆纤维(即为高长短轴比ε)在迎风角约为θ=45°时质量因子总体较高,即具有较优的综合过滤性能;而对弱惯性粒子,则扁长型椭圆纤维长轴平行来流方向(θ=0°)时,总体过滤性能较优.A numerical scheme was developed for calculating the inertial collection efficiencies of particles by elliptical fibers and filtration pressure drop.The viscous flow fields for single elliptical fiber were determined by solving the Navier-Stokes equation numerically,and the effects of the following parameters,such as orientation angle(θ),cross-section aspect ratio(ε)and packing density(C)on the filtering performance were discussed.The results showed that the filtration pressure drop for elliptical fibers increased with the increasing aspect ratio for large orientation angle but decreased for small orientation angle.With the same cross-section aspect ratio,the filtration pressure drop increased with the increasing orientation angle.The efficiency of elliptical fibers with larger orientation angle and cross-section aspect ratio was higher than that of circular fibers for intermediate and high-inertia particles,whereas for low-inertia particles,the elliptical fibers with small orientation angle showed higher collection efficiency.The quality factor,an indicator of the ratio of the collection efficiency to the pressure drop,was used to evaluate the comprehensive performance of the elliptical fibers.It was found that the elliptical fibers with large aspect ratios(i.e.,long and slim elliptical fibers)showed higher the quality factor(i.e.,better comprehensive filtration performance)in capturing intermediate and high-inertia particles when the orientation angle was about θ=45°.For low-inertia particles,the elliptical fibers with major axis parallel to the incoming flow might have filtration performance advantages.

关 键 词：气溶胶过滤 椭圆纤维 过滤阻力 惯性捕集效率 数值计算 

分 类 号：X701.2[环境科学与工程—环境工程] TQ021TU834[化学工程]