通过一维仿真的分析方法，在某六缸柴油机以及相同缸径冲程单缸机的标定工况下，研究增压方式对柴油机换气过程以及整机性能的影响规律，并总结出了最佳配气相位的选取原则。由于涡轮增压六缸机和模拟增压单缸机增压方式不同，导致进排气状态不同，采用相同优化顺序和计算方法，单缸与六缸计算所得到的最佳配气相位差异明显，选取原则也有所不同。涡轮增压六缸机和模拟增压单缸机的最佳进气门晚关角和排气门早开角的选取原则相同，分别为“充量系数最大”和“有效功率最大”，但具体角度不同；最佳进气门早开角的选取原则分别为“实际进气量最大”和“有效功率最大”；最佳排气门晚关角的选取原则分别为“实际排气量最大”和“有效功率最大”。在2 500 r/min标定工况下，六缸优化方案的功率、扭矩等动力性指标相较于单缸方案和原机方案分别提高约1.5%和2.6%，循环进气量分别提高约1.2%和3.4%。验证了仿真方法的有效性。
Through 1D simulation analysis method, the influences of turbocharging mode on the air exchange process and the performance of diesel engine were studied and the selection principle of optimal valve timing was summarized under the rated conditions of a 6-cylinder diesel engine and a single-cylinder engine with the same bore and stroke. The intake and exhaust conditions of turbocharged 6-cylinder engine and simulated turbocharging singlecylinder engine were different due to different turbocharging modes between them. The difference of optimal valve timing angle between 6cylinder and single-cylinder was obvious by using the same optimization sequence and calculation method and hence the selection principle could be different. The selection principles of optimal IVC and EVO were the maximum charging efficiency and the maximum effective power respectively, which were the same for 6cylinder and single-engines with different angles. The selection principles of optimal IVO for both engines are the maximum actual intake volume and the maximum effective power respectively, and the selection principles of optimal EVC for both engines were the maximum residual gas coefficient and the maximum effective power respectively. Compared with single-cylinder and original engine scheme, the power indexes of power and torque for 6cylinder optimization scheme increased by about 1.5% and 2.6% respectively and the circulating air intake increased by about 1.2% and 3.4% respectively under the rated condition of 2 500 r/min. The validity of simulation method was finally verified.
