基于VLBM方法研究柴油机多孔微粒捕集器渗流机理

Study on Seepage Mechanism of Diesel Porous Particulate Filter Based on VLBM

摘要: 柴油机依靠其良好动力性和经济性的优势，自问世以来，便在车辆、船舶等动力装置得到广泛应用。与此同时，柴油机微粒排放物也带来严重的污染问题，引起人们的广泛关注。本文采用体积格子玻尔兹曼方法(VLBM)，在孔隙尺度上，论述了多孔介质过滤体结构和进口速度对捕集器通道模型内流场的影响，为柴油机微粒捕集器的数值模拟研究提供一个新的思路。结果表明，孔隙度越大，微粒捕集器孔道模型中的流场越稳定，进出孔道压差越小；相比于孔隙度，过滤体厚度对流场影响较小，然而过滤体厚度越大，进出口孔道压差越大；进口速度越大，流场越紊乱，压差越大。

Abstract: Diesel engines have been widely used in vehicles, ships and other power plants since they were invented because of their good power and economic advantages. At the same time, diesel particu-late emissions also bring serious pollution problems, causing widespread concern. In this paper, the influence of porous media filter structure and inlet velocity in the flow field of the trap passage model is discussed on the pore scale by using the volumetric lattice Boltzmann method. It provides a new idea for numerical simulation of diesel particulate trap. The results show that the larger the porosity is, the more stable the flow field is and the smaller the pressure difference between inlet and outlet is. Compared with porosity, the thickness of the filter has less influence on the flow field. However, the greater the thickness of the filter, the greater the pressure difference between the inlet and outlet channels is. The larger the inlet velocity is, the more turbulent the flow field is, the greater the pressure difference is.