排气歧管形式和加工工艺对汽油机性能影响的研究

Investigation on Effect of Exhaust Manifold Type and Processing on Gasoline Engine Performance

通过对某1.5L排量4缸汽油机排气歧管进行设计形式及加工工艺的改进,将原4-1式排气歧管改为类4-2-1式,加工工艺从铸造改为采用弯管式冲压焊接。ANSYS FLUENT计算结果表明:新设计排气歧管流速均匀系数达到0.910～0.935。GT-POWER性能模拟及发动机性能试验发现:新设计排气歧管对汽油机的扭矩特性,尤其是对驾驶性能尤为重要的低速扭矩区域改善明显,低速扭矩最高可提高5%,排气歧管质量减轻约40%。

Exhaust manifold of a 1.5 L four cylinder gasoline engine was improved, the type 4 1 was re placed by type 4-2-1 and the forming technique was changed from casting to stamping-welding. The calcula tion results by using ANSYS FLUENT reveal that flow velocity uniformity coefficient of the new manifold reaches 0. 910-0. 935. Analysis by GT-POWER and actual engine test results show that the new manifold significantly improves engine torque characteristics, especially low speed torque increases by 5%. In addi tion, the exhaust manifold weight reduces up to 40%.