可控进气涡流对柴油机低负荷性能影响的研究

就双进气道可控进气涡流系统改善大功率增压中冷柴油机低负荷性能的作用机理进行了理论分析与试验研究。研究结果表明：在低负荷工况下，双气道进气时的涡流强度小于螺旋气道，大于直流气道；螺旋气道进气流量较之双气道虽有所减少，但其涡流比仍保持较高水平，致使缸内爆压、预混合燃烧量和最大放热速率均较大。理论计算与试验结果证明，采用双进气道可控进气涡流系统是改善大功率柴油机低负荷性能的一个有效途径。

Effect of the Variable Inlet Swirl Intensity on the Performance of Low Load in a Heavy Duty Diesel Engine

The mechanisms of combustion improvement at low load operation in a heavy-duty supercharging diesel engine equipped with a twin inlet ports and variable inlet swirl intensity are analyzed experimentally and theoretically. The results show that the twin intake port gives lower swirl ratio than that of helical port under low load condition but higher than that of directed intake port. The swirl intensity still remains a high level although helical inlet port shows a slight decrease in flow rate compared to the twin inlet port, resulting in a relatively high cylinder pressure, large premixed combustion and high rate of heat release. Theoretical and experimental results suggest that the engine performance at low load can be improved with the variable swirl twin inlet port.