Three-dimensional ptv study of the surrounding flow and wake of a bubble rising in a stagnant liquid

The particle tracking velocimetry measurement technique was used to measure the whole-volume, three-dimensional, transient velocity field generated by a single air bubble rising in stagnant water in a small diameter pipe. The three-dimensional flow field was reconstructed using a stereoscopic technique. Conditional averages of the velocity fields for the situations when the bubble rises at the center of the pipe, and close to the pipe wall, were determined. The turbulent motion generated in the continuous liquid phase for both situations was studied.