王远，刘双喜，陈皓，牟江峰

（中国汽车技术研究中心，天津 300300）

摘要：针对某汽油机原铸铁排气歧管结构复杂、重量较重、不能搭载满足国Ⅴ排放法规要求的催化器等情况,通过重新设计一款冲压焊接紧耦式排气歧管来解决上述问题。利用一维仿真软件GT-Power对发动机工作过程进行计算分析,得出排气歧管最佳的结构尺寸和连接走向。建立排气歧管三维模型,通过三维仿真软件Star-ccm+对排气歧管内气流流动分布进行分析优化,得到最优的排气歧管设计方案,并与原排气歧管进行性能对比试验验证。

关键词：紧耦式排气歧管; 汽油机; 一维仿真; 三维仿真; 优化设计

Abstract：The original cast iron exhaust manifold of a certain gasoline engine has some problems. For example, the structure is complicated and heavy, and cannot meet China 5 Emissions standards. In order to solve these problems, a closely coupled exhaust manifold is designed. Using GT-Power to calculate and analyze the working process of the engine, the optimal structure size and connection trend of the exhaust manifold are obtained. Star-ccm+ was used to build the 3D model of the exhaust manifold, analyze and optimize the distribution of air flow in the exhaust manifold, and get the optimal design scheme of the exhaust manifold. Engine tests were also conducted to compare the performance of the original and the new exhaust manifold.

Key words: Tightly Coupled Exhaust Manifold; Gasoline Engine; 1D Simulation Analysis; 3D Simulation Analysis; Optimization Design