Abstract The inflow uniformity before selective catalytic reduction (SCR) catalyst carrier is a major issue for DeNO x capability of diesel engine after-treatment. Through the construction of the numerical model and CFD simulation of six perforated plate variations with different structural and positional characteristics, the influence of perforated plates on the uniformity of the airflow velocity at the inlet of the SCR catalyst carrier was analyzed. Comparison of different perforated plate variations shows that the encircling flow is a major hindrance to achieve higher inflow uniformity. Enclosed flow passage can remove the encircling flow and increase inflow uniformity at the cost of increased pressure drop. Rational layout of the perforated plate can achieve uniformity increase, while decrease pressure drop. High-velocity exhaust coupled with larger holes can improve both uniformity and pressure drop. The uniformity index increased from 97.6% of the original design to 98.7% of the optimized design, while pressure drop increased from 11.20 to 12.09 kPa. Weighing the relationship between inflow uniformity and pressure drop is an issue worthy of attention.

中文翻译：

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基于CFD模拟的SCR流入均匀性优化

摘要 选择性催化还原（SCR）催化剂载体前的流入均匀性是影响柴油机后处理脱硝能力的主要问题。通过对六种不同结构和位置特征的多孔板变量的数值模型构建和CFD模拟，分析了多孔板对SCR催化剂载体入口气流速度均匀性的影响。不同穿孔板变化的比较表明，环绕流是实现更高流入均匀性的主要障碍。封闭的流道可以以增加压降为代价，去除环流，增加流入的均匀性。穿孔板的合理布局可以实现均匀性增加，同时降低压降。高速排气加上更大的孔可以改善均匀性和压降。均匀度指数由原设计的97.6%提高至优化设计的98.7%，压降由11.20kPa提高至12.09kPa。权衡流入均匀度与压降的关系是一个值得关注的问题。