汽油机排气歧管结构的优化及验证

分析某四缸汽油机排气歧管结构设计存在的缺陷并对其进行改进优化,采用数值模拟仿真软件分别对排气歧管改进前和改进后通道的各缸排气背压及歧管排气气流均匀性进行仿真,仿真结果表明改进后排气歧管结构能明显降低排气背压和各通道不均匀性。最后对原歧管和改进后歧管搭载的汽油机进行了台架对比试验,试验结果表明搭载改进后排气歧管的汽油机不仅提高了原机的外特性扭矩而且降低了燃油消耗,进一步验证了排气歧管结构改进优化的可行性。

Exhaust Manifold Structural Optimization and Validation of a Gasoline Engine

Analyze structural defect which exist in exhaust manifold of some four cylinders gasoline engine and optimize it. Use numerical modeling simulation software to analyze exhaust back pressure （EBP） and exhaust flow＇ s homogeneity of before and after optimization. Analysis shows that EPB and homogeneity of each cylinder are both reduced. Contrast the gasoline engines which carry original manifold and optimized manifold at table test. The result show that optimized manifold not only advance external characteristic torque but also reduce fuel consumption. Feasibility to optimize structure of exhaust manifold is validated by this table test.