トレーサ軌跡抽出法を用いた速度ベクトル分布の画像計測

開水路流れへの適用

抄録

The digital image processing has been applied recently to flow measurement in order to obtain quantitative data from various visualized flow phenomena As an effective way for the measurement of flow velocity vector distribution, a tracer method has been usually adopted for flow visualization and also the velocity vectors have been calculated from the photographic pictures of tracer paths. This technique by using the photographs, however, needs some complicated procedures of the processing to determine the flow directions.
In this study, the authors propose and develop the image processing system to determine the flow directions more easily. This system consists mainly of a TV camera, an image frame memory, and a minicomputer. The image frame memory is specially capable of extracting the tracer paths. The minicomputer and its software system calculate the travelling distances of the tracer particles floating during a constant period in order to obtain the flow velocity vector distribution. And this system was actually applied to an open channel flow.
As a result of this study, the following facts were specifically confirmed:
(1) The travelling distance and direction of the tracer particles were determined precisely by matching the tracer particle image at the starting point to the tracer path image.
(2) The tracer path lines, the velocity vectors, and their distribution were obtained.