高强化柴油机进气流动特性研究

Research on Intake Flow Characteristics of Highly Intensified Diesel Engine

针对某高强化柴油机,运用发动机三维仿真软件converge建立模型,并通过柱坐标系下气门间隙环带的总速度和速度分量以及缸内不同截面下的速度分布规律,对切向进气道和螺旋进气道出口处的气体流动特性进行研究。研究发现:气流通过切向气道的速度整体略高于通过螺旋气道的速度,径向速度的变化趋势更贴近于总速度;在进气过程中,气门间隙处会发生回流,这是由于气流通过两气道后相撞,产生了小的涡团。回流的影响虽然很小,但综合考虑是不可以完全忽略的。

A model for a highly intensified diesel engine is established by using the engine three-dimensional simulation software converge,and the gas flow characteristics at the outlet of tangential inlet and helical inlet is studied through the total velocity and velocity component of valve clearance ring in cylindrical coordinate system and the velocity distribution law of different sections in cylinder.It is found that the overall velocity of airflow through tangential airway is slightly higher than that through spiral airway,and the variation trend of radial velocity is closer to the total velocity.In the process of intake,backflow will occur at the valve clearance due to the collision of air flow through the two air passages resulting in small vortices.Although the impact of reflux is very small,it should not be completely ignored.