四气门柴油机进气道流通特性的研究

每缸采用四气门的发动机能进一步降低排放，提高发动机的动力性和经济性本文介绍了直喷式柴油机的四气门进气系统，分析了该系统在充气效率和燃烧方面的特点文中作者进行了螺旋气道与不同流通面积的切向气道的组合试验讨论了四气门进气系统进气道的流通特性及进气道不同进口流通面积对进气流量和涡流动量的影响研究结果表明采用四气门进气系统，进气流通面积增加３９％；另外，切向气道和螺旋气道的进气流量直接影响着缸内涡流的形成，最佳的涡流效果和切向气道与螺旋气道的流量之比密切相关本文为四气门高速直喷式柴油机的进气系统设计提供了依据

Study on the Flow Characteristics in Inlet Passages of 4-Valve D.I. Diesel Engine

With 4 valves per cylinder, the emissions of engines can be reduced further,the dynamic and economic performance can also be improved. The features of 4-valve inlet system of D.I. diesel engine are analyzed with emphasis on volumetric efficiency and combustion experiments of inlet ports with different inlet areas are carried out,and the flow characteristics in inlet passages are discussed. The impacts of different inlet port area on the flow rate and the swirl momentum are given. Investigation results show that the flow area of valve sector increases by 39 percent. Besides the ratio of the flow rate of tangential port and the flow rate of swirl port is the critical factor to form flow fields in cylinder,and the best swirl momentum is formed under a special ratio of flow rate,which provides a basis for 4-valve inlet system design of high speed D.I. diesel engine.