Motion of Bubble

The bubbly flow is an important flow pattern in fluids engineering. A variety of bubbly flows have been witnessed so far; bubble size and bubble volume fraction are two factors that affect the appearance of the bubbly flow. In consideration of the shortage of numerical simulation in the presence of bubbly flows, the supplement of the knowledge of bubbly flows depends heavily on the advancement and application of measurement techniques. Another point associated with bubbly flows lies in that many conclusions obtained are associated with certain experiment rig or specific engineering application and are therefore difficult to generalize. In this section, two cases relevant to the bubble trapped in liquid are presented. One is the rising bubble in stationary water and the other is the bubble released in horizontal water flow. Experimental techniques, in conjunction with developed image-processing code, are used. Geometric and motion quantities of bubble are adopted to describe the bubble characteristics.