气道及燃烧室对米勒循环发动机性能的影响

Effect of Intake Port and Combustion Chamber on Performance of Miller Cycle Engine

基于CONVERGE软件对比分析了中、高滚流比进气道及挤气结构对缸内流场及燃烧特性的影响,仿真与试验变化趋势较为一致,结果表明,在2500rpm 1.2MPa工况下,相比高滚流气道,中滚流比气道及挤气方案缸内流场的变强,燃烧特性变好,油耗分别降低0.5%、2.13%;在6000rpm 1.5MPa工况下,中滚流气道流场及燃烧变差,功率降低2.2%,而挤气方案流场降低幅度相对较小,且流场分布相对较好,爆震倾向变好,燃烧相位提前,功率提高4.17%。

Based on the CONVERGE software,the influence of medium and high tumble intake port and squish structure on the flow field and combustion characteristics in the cylinder is compared and analyzed,and the simulation and test trends are more consistent.The results show that under the condition of 2500rpm 1.2MPa,compared with the high tumble port,the in-cylinder flow field of the middle tumble ratio port and the squish scheme becomes stronger,the combustion characteristics become better,and the fuel consumption is reduced by 0.5% and 2.13 % respectively.Under the condition of 6000rpm 1.5MPa,the flow field and combustion of the middle tumble port become worse,and the power is reduced by 2.2%,while the flow field of the squishing scheme is relatively small,and the flow field distribution is relatively good,and the knocking tendency becomes better,the combustion phase is advanced and the power is increased by 4.17%.