柴油机微粒捕集器非对称孔道内流场和压降特性模拟  

Numerical simulation for flow and pressure drop characteristics in asymmetrical channels of diesel particulate filter

作　　者：李志军[1] 王楠[1] 张立强 黄群锦 魏所库 张彦科[1] 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]天津市圣威科技发展有限公司,天津300132

出　　处：《吉林大学学报（工学版）》2016年第6期1892-1899,共8页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(51276128);科技部中欧中小企业节能减排发展专项基金项目(SQ2013ZOA100012)

摘　　要：采用Fluent建立了柴油机微粒捕集器(DPF)非对称孔道的三维模型,计算了孔道内的流动和压降特性,分析了DPF内碳烟微粒的沉积过程,比较了不同壁面渗透率和碳载量下对称孔道与非对称孔道中的压降特性。研究结果表明:进口孔道速度沿轴向先增大后减小,出口孔道速度沿轴向逐渐减小;进口孔道静压沿轴向先减小后增大,出口孔道静压沿轴向逐渐减小;碳烟微粒总是先在孔道的后端沉积,随着碳载量增大,碳烟微粒沿孔道轴向分布逐渐趋向于均匀;绝对碳载量系数大于0.3时,非对称孔道相对于对称孔道具有较小的压降;进、出口孔道比例越大,压降受排气流量的影响越大。The 3D model of a Diesel Particulate Filter （DPF） with asymmetrical channels was established in Fluent. Based on numerical model, the fluid flow and pressure drop characteristics were simulated, the soot loading process was analyzed, and the pressure drops in asymmetrical channels and symmetrical channels were compared. The results show that, along the inlet channels, the flow velocity magnitude increases at first and then decreases, while the static pressure decreases first and then increases. Along the outlet channels the flow velocity increases while the static pressure decreases. At the beginning of soot loading process, larger amount of soot loading is found in the downstream half of the channel. As the soot loading increase, the distribution of soot along the axial direction becomes uniform. The pressure drop in the asymmetrical channels is lower than that in the symmetrical channels. The coefficient of the absolute soot loading of the asymmetrical channels is above 0. 3. As the inlet-to-outlet ratio increases, the influence of the inlet mass flow rate on the pressure drop becomes more significant.

关 键 词：动力机械工程 柴油机微粒捕集器 非对称孔道 流场 压降 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]