4气门火花点火式车用发动机缸内滚流和涡流运动的研究

近年来的研究结果表明，４气门火花点火式发动机具有明显的优越性，是车用汽油机的发展方向。本文报道了稳流气道试验台上对一台４气门汽油机以５种不同结构的进气道进行了气道流动特性的试验，用激光多普勒测速仪的在发动机倒拖工况下测量了缸内的空气运动，得到如下结论：４气门汽油机的缸内宏以空气流动主要绕与气缸中心线垂直方向旋转的滚流运动；高位切向式双进气道可获得较高的滚流速度和平均流量系数，是４气门汽油机理想的进

Investigation of Tumble and Swirl Motion in the Cylinder of 4-Valve a S.I.Engine

n recent years, 4-valve S. I. engines have become the development trend for automotive engines. In this paper, flow characteristics of five dual-intake ports with different configurations were tested on a steady flow rig, and air flow in the cylinder were measured by LDA on a motored 4-valve S. I. engine. The experimental results show that the in-cylinder air flow in a 4-valves S. I.engine is mainly a tumble motion which rotates around an axis perpendicular to the centerline of the cylinder. Tangential dual-intake port with higher entrance position can produce higher average tumble speeds and higher flow coefficients, and is therefore the ideal intake port configuration for4-valve S.I. engines. When one of the two ports of the dual-intake configuration is closed, the in-cylinder flow becomes an oblique swirl, which is the combined motion of tumble and swirl.