3-D PTV Measurement of Bubble Rising Flow in a Cylindrical Vessel

摘要

Detailed information on the fluid flow around a bubble is required for better understanding of metallurgical reactions in the steelmaking processes agitated by gas injection. In the current research a model has been used for a cold simulation experiment of water-air two-phase flow. Previous studies have focused mainly on the "time-averaged flow structure around bubbles. However, it is well known that the movement of a bubble is transient and three-dimensional, and hence, the flow around the bubble is also transient and three-dimensional. This study was carried out to elucidate the flow around a single bubble rising in a cylindrical water vessel. 3-D PTV (Particle Tracking Velocimetry) is used to analyze the movement of gas-bubbles in the water bath. The water flow around a single bubble is investigated by the technique of PIV based on visualization and image processing. An experimental apparatus is set up to generate a bubble of known volume rising from bottom. Velocities of the bubble and the surrounding fluid are obtained simultaneously by a three consecutive time picture cross-correlation 3-D PTV. A new technique that can measure the fluctuating velocity field and ensemble averaged kinetic energy from the time series of particle imaging is developed in data processing.