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 techni que. Conditional averages of the velocity fields for the situations when th e 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 f or both situations was studied.