螺旋气道变截面进气的缸内充量分层模拟研究

构建了YN33共轨柴油机螺旋气道-气门-气缸的CAD模型,划分螺旋气道的进气口为不同进气截面,并通过在各个截面分区进气,以及时序分区进气实现缸内的充量分层。研究表明:变截面进气时,进气截面下半部进气量比上半部进气量多7%,而右下区的进气会在缸内形成较为均匀的分布,其它区域进气则会形成浓度场各异的分布特性。三段时序进气条件下,4个区域进气对缸内进气总量贡献的差异由前段进气与后段进气所决定,且后段进气影响更大;在分布特性上,进气截面右上区和右下区的前段进气会在缸内形成明显的上稀、下浓分布特点,而后段进气均会在缸内形成上浓、下稀的分布。

Stratified Simulation of In-cylinder Charge of Spiral Airway Variable Cross-Section Intake

Construct a CAD model of the helical intake-valve-cylinder of the YN33 common-rail diesel engine,divide the inlets of the helical intake passages into different intake cross sections,and realize the in-cylinder charge stratification by partitioning intake air in each section and timing zoned intake air.The research shows that when the variable cross-section intake,the intake air volume in the lower half of the intake section is 7%more than that in the upper half,while the intake air in the lower right section will form a more uniform distribution in the cylinder.The distribution characteristics of the concentration field are different.Under the three-stage timed intake condition,the difference of contribution of the four regional intakes to the total intake of the cylinder is determined by the intake of the front section and the intake of the latter section,and the influence of the intake of the latter section is greater;in terms of distribution characteristics,the intake of the front section of the upper right section and the lower right section of the gas section will form a distinct upper and lower concentration distribution in the cylinder,while the latter section will form an upper thick and lower lean distribution in the cylinder.