邹健，吴建财，严金龙

（常柴股份有限公司，江苏 常州，213002）

摘要：公司某四缸增压柴油机在低速段扭矩偏小，分析可以通过重新设计排气歧管，使这种情况得到改善。使用CFD软件OpenFOAM对原排气管内部流场进行了计算分析，根据分析结果设计了新的双脉冲排气歧管，并对比了两种排气歧管的分析结果。对新排气管进行了装机试验，结果显示在装配了新管后，柴油机在低速段的扭矩有所提升，并且排放也有一定改善。

关键词：柴油机；排气管；CFD；OpenFOAM

Abstract: The torque of a 4-cylinder turbocharged diesel engine at low speed was too small. A new exhaust manifold was designed to improve this situation. The internal flow field of the original exhaust manifold was calculated by using OpenFOAM.  According to the results of the analysis, a new dual pulse exhaust manifold was designed, and the comparison of analysis results of two exhaust manifolds was made. The test results after assembling the new exhaust manifold shows that the torque at low speed increased and the emissions of the diesel engine was reduced.

Key words: Diesel Engine; Exhaust Manifold; CFD; OpenFOAM