Time resolved PIV measurements with systems of bubbles rising in water

摘要

A planar particle image velocimetry (PIV) experiment with simultaneous measurement of the velocity distributions of the individual phases in bubly two phase flow is performed with a digital high speed camera in order to examine the velocity distribution around systems of bubbles rising in water. The simultaneous measurement of two phass with different velicities is achieved by a mask technique applied in the MQD evaluation algorithm. 576 measurements of the velocity distribution per second give insight into the temporal development of the wake flow downstream of the bubbles. The bubbles generate vortices in the water and their separation from the bubbles is investigated. We perform measurements with a single bubble and systems of bubbles rising in water to show the differences in turbulence production.