The impact of catalyst distribution within the porous wall of a coated gasoline particulate filter on its catalytic performance is investigated. Sections of catalyzed filter wall with different amounts of washcoat and different levels of uniformity are digitally reconstructed from tomography data. A coupled problem involving the exhaust gas flow and the transport and reaction of a dilute species in the reconstructed structures is solved using the lattice Boltzmann method. The resulting model is verified and its accuracy is assessed for first-order reactions and those with inhibition kinetics. Computed washcoat effectiveness values agree well with the Thiele modulus theory. Improvements in catalytic conversion and washcoat effectiveness of uniform washcoat distribution are observed with increased washcoat loading. These effects are quantified and the benefits are found to be limited to the transitional regime. The uniform washcoat distribution is shown to be beneficial for both filtration and conversion performance.

研究了催化剂分布在涂层汽油微粒过滤器的多孔壁内对其催化性能的影响。从层析成像数据以数字方式重建具有不同修补基面量和不同均匀度的催化过滤器壁的截面。使用格子Boltzmann方法解决了涉及废气流以及稀疏物质在重建结构中的传输和反应的耦合问题。验证了所得模型，并评估了一级反应和具有抑制动力学的反应的准确性。计算的修补基面涂层有效性值与Thiele模量理论非常吻合。随着增加的修补基面涂料载量，观察到了催化转化率和修补基面涂料分布均匀的修补基面涂料有效性的改善。量化这些影响，发现收益仅限于过渡制度。均匀的修补基面涂层分布对过滤和转化性能均有利。