用LDA研究柴油机涡流室内空气运动

本文介绍了采用二维氩离子ＬＤＡ（激光多普勒测速仪）对柴油机涡流室内空气运动特性的最新测试结果。测量结果表明：涡流室内气体平均速度及紊流强度仅为发动机曲轴转角的函数，在上止点附近随发动机转速升高，最大值出现时刻相对曲轴转角位置基本保持不变。这一点区别于使用ＨＷＡ（热线风速仪）对涡流室的测量。吊钟型涡流室内的空气涡流以刚体涡流为主。本文描述了吊钟型涡流运动中涡核的运动轨迹，提出了进一步改进涡流燃烧系统

A Study on Air Motion in Diesel Swirl Chamber by LDA

In this paper, a new measuring result of the air motion in swirl chamber of a diesel engine by the 2D Arion LDA was presented. It was found that the mean velocity and turbulence intensity are the function of the crank angle. Despite the engine speed increased, the peak values of mean velocity or turbulence intensity appeared at the same crank angle approximately. This result is different that of HWA test. The locus of vortex center in bell type swirl chamber the air motion of which can be regarded as a solid vortex was given in detail. Some suggestions for improving the swirl combustion system had also been given.