投影・散乱光画像を利用したマイクロバブル衝突噴流の3次元速度計測

抄録

Microbubble flows are employed in a variety of engineering applications, such as the cleaning of surfaces, drag reduction in ship hulls and various chemical plant processes. Especially for surface cleaning, the measurement of the bubble and liquid flow speed is required for the better understanding of cleaning efficiency. PIV is a useful tool for the measurement of the fluid velocity, because it is possible to measure planar flow structures without disturbing the flow field. To apply PIV to microbubble flows, the separation of microbubbles and liquid in the acquired images is required. In the present study, we present a velocity measurement system for gas-liquid two phase flows that employs phase discrimination based on the different optical properties of the bubbles and solid tracer particles. By using two cameras, the 3-dimensional position and velocity of both phases in microbubble impinging jet was successfully measured.