刘会珍   

    摘要：一般就四缸发动机而言,由于进排气门重叠开启,会出现排气废气倒流现象,影响发动机的进气充量,导致发动机性能偏低。本文从排气歧管结构对进气充量影响进行分析,得出导致倒流可能存在的原因,同时就分析结果提出优化方案对排气歧管结构进行优化,进行试验验证,确定最终的排气歧管结构,有效地提高发动机性能。

    关键词：发动机;热力学性能;排气歧管;气门重叠

    Abstract: In general,exhaust gas backflow often occurs in four cylinder engines because the intake and exhaust valves close or open at overlap angle,leading engine performance deteriorated.In this paper was studied on influences of exhaust manifold structure on intake charge,as well as backflow factors.The solution was proposed to optimize the exhaust manifold structure according to simulation results.Tests were carried out to validate the simulation results.The proposed exhaust manifold structure might significantly improve engine performance.

    Keywords: Engine;Thermodynamics Performance;Exhaust Manifold;Valve Overlap

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