MEASUREMENT OF THE FLOW DISTRIBUTION IN AN INTERNAL COMBUSTION ENGINE BY HIGH SPEED PHOTOGRAPHS OF ELECTRO-OPTICAL SHUTTER

在发动机的燃烧分析中，测量气缸内的流速是非常重要的。利用流动显示技术来补充激光多普勒测速等局部速度数据是测量缸内流动最有效的方法之一。在本报告中。示踪剂的轨迹是由高速摄影使用光电快门命名为PLZT。在第一年。对高速摄影测量系统进行了基础研究。Polysteren是流动的示踪剂。第二年的改进是除了PLZT百叶窗外，还采用了机械百叶窗来去除照明的背景光，并使用了三聚甲醛作为示踪剂。机械快门的速度提高到1/100秒左右，拍出了清晰的照片。三聚乙醛示踪剂也能有效地跟踪柱体流动。经过这些改进。并与LDV数据进行了比较，验证了系统的准确性。通过对图像的分析，明确了缸内流动的空间分布和流型的循环变化。同时也存在着三维流场分析方法不完善、数据处理困难等问题。

It is very important to measure the flow velocity in the cylinder from the comustion analysis of an engine. One of the most effective method to measure the in-cylinder flow is the flow visualization technique to supplement the local velocity data such as from the Laser Doppler velocimetry. In this report. The locus of the tracer was taken by a high speed photographs using the electro-optical shutter named PLZT.At the first year. the basic research was made about the measuring system to take high speed photos. Polysteren was used for the tracer of the flow.The improvements of the second year are the adoption of the mechanical shutter in addition to the PLZT shutter to remove the back groud light of illumination and the utilization of the metaldehyde as the tracer. The speed of the mechanical shutter was risen to about 1/100 second and it brought the clear photos. The metaldehyde tracer was also effective to trace the cylinder flow.After these improvement. The accuracy of this system was examined to compare with the data of LDV. The spatial distribution of the in-cylinder flow and the cyclic variation of the flow pattern was clarified from the analysis of the images.The problems were also remained such as the analitical method of the three dimensional flow and the difficulties of the data processing.