Experimental Studies of Small Air Bubble Motion in Turbulent Pipe Flow

The main objective of this research is to collect statistical information concerning momentum phase coupling between the continuous phase and a single air bubble in turbulent flow in a horizontal pipe, and to develop data that can be used for the verification of numerical modeling efforts. In comparison with vertical pipe bubble flow, horizontal bubble flow has received less attention, especially from the experimental side. Thus, an experimental investigation of bubble behaviour in a horizontal square pipe was performed. Tracking of a single bubble released in water flow in a 56.8 mm × 56.8 mm square pipe was performed to provide a basis for characterizing the behaviour of the single bubble in turbulent pipe flow. A Shack Hartman Wavefront Sensor and a High Speed Video Camera were used to collect images at various points downstream from the bubble injection point, providing information on bubble size, velocity, and spatial location as a function of Reynolds number. Velocity profile information of the continuous phase was collected using Particle Image Velocimetry (PIV) in order to perform a complete characterization of the flow. The data collected using PIV coupled with the analysis of the three-dimensional trajectory of a single bubble provides information about parameters such as a gas slippage velocity with the fluid phase and bubble distribution as a function of both Reynolds number and mean velocity profile.