画像処理技術を用いたスラグ気泡流動特性の計測技術 第２報 スラグ気泡流のＷａｋｅの流れ場と液膜流速計測技術

Abstract

Geysering may be induced during start-up in natural circulation boiling water reactors. It is necessary for simulation of this flow instability to model the coalescence mechanism and condensation process of slug bubbles. In this work, image data processing technique using a digital video camera has been developed to measure slug flow characteristics. In this technique, ultraviolet lighting with high frequency power source, laser sheet and stroboscope whose lighting frequency can be regulated are used as lighting and small nylon particles mixed into water are adopted for tracers. The developed measurement technique are applied for slug bubbles rising in stagnant water, and coalescence process of slug bubbles, liquid film velocity surrounding a slug bubble and velocity field in the wake region are measured. From these results, the capability of the developed measurement technique and the measurement accuracy are discussed.