柴油机颗粒捕集器内颗粒层不均匀分布的数值研究  

Numerical Investigation into the Non-uniform Soot Layer Distribution in a Diesel Particle Filter

作　　者：孟忠伟[1] 宋蔷[2] 

机构地区：[1]西华大学交通与汽车工程学院,四川成都610039 [2]清华大学热能工程系,北京100084

出　　处：《西华大学学报（自然科学版）》2011年第1期1-4,51,共5页Journal of Xihua University:Natural Science Edition

基　　金：国家"九七三"重点基础研究项目(2002CB211600);四川省教育厅科技创新团队(KYTD201003);四川省教育厅青年基金项目(10ZB078)

摘　　要：针对壁流式柴油机颗粒捕集器捕集颗粒物的工作过程,建立了描述通道内流场和颗粒层分布的一维非稳态模型。通过数值计算,研究了壁面渗透系数不均匀对颗粒层分布和过滤压强的影响。研究结果表明:壁面渗透系数不均匀造成颗粒沉积高度的不均匀,渗透系数大的位置颗粒层沉积高度大。在相同的不均匀偏差条件下,平均壁面渗透系数越低,颗粒层高度的不均匀程度越大,但随过滤时间的增加,颗粒层高度的相对偏差逐渐减小,各位置过滤速度趋于一致,颗粒层高度均匀增长。在正常的过滤体孔隙结构不均匀分布条件下,过滤压降基本不受影响。A one-dimensional unsteady model simulating the trapping process of fine particles by wall-flow filter was developed to simulate the flow field and particle layer distribution in a channel.Numerical simulation was conducted to investigate the influence of non-uniform distributed wall permeability of the filter on the particle layer distribution and filter pressure drop.The results showed that the non-uniform distributed wall permeability of filter caused the non-uniform distribution of soot layer,the position with higher wall permeability led to higher soot layer thickness.With the same relative deviation of wall permeability in different filter length,the lower average wall permeability led to higher non-uniform soot layer distribution.The relative deviation of soot layer thickness decreased gradually with the loading time,because the filtration velocity of different position in channel was tended to uniform distribution with the loading time,and led to uniform increasing rate of soot layer thickness.However,the non-uniform distributed wall permeability had little influence on the pressure drop under the normal condition.

关 键 词：壁流式 柴油机颗粒捕集器 壁面渗透系数 过滤压降 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]