四气门发动机可变进气结构的斜轴涡流特性

Inclined-Axis Swirl of 4-Valve Spark Ignited Engine with Variable Intake Device

为了研究滑动式可变进气结构对缸内斜轴涡流特性的影响.利用稳流气道试验台对这种可变进气结构的涡流和滚流进行了实验,采用特定方法计算了可变进气结构的缸内斜轴涡流特性.研究表明,在这种可变进气结构作用下,缸内气体运动不再是单纯的涡流运动或滚流运动,而是斜轴涡流运动;并在一定进气门及进气道出口结构前提下,存在一个临界的气门升程;在临界气门升程以后,缸内开始形成较为稳定的斜轴涡流运动;这种可变进气结构可有效地调节斜轴涡流运动的组成.除具有纯滚流特点的S1阀片位置外,缸内气体斜轴涡流运动强度与单边气道截面被遮住的面积成正比.

In order to analyze the effect of the sliding variable intake device on the inclined-axis swire in the cylinder,the swirl and tumble were firstly measured on a steady flow bench. Based on the measured swirl and tumble, the evaluations of the inclined-axis swirl were calculated with a specified method. The results are as follows. Firstly, influenced by this variable intake device, the in-cylinder air motion is the resultant swirl—an inclined-axis swirl instead of single swirl or tumble. Secondly, with the structure of intake valves and intake channel outlet, there is a critical intake valve lift and when the valve lift is above the critical value, the steady inclined-axis swirl is formed. Thirdly, this variable intake device can adjust the constitution of the inclined-axis swirl efficiently. Lastly, the strength of inclined-axis swirl is directly proportional to the shadowed area of the single channel except for the S1 valve position where the in-cylinder motion is only tumble.