Bubbly Flow Identification Using Particle Image Velocimetry

Abstract

The shape of a rising air bubble in a pipe flow is investigated with the Particle Image Velocimetry (PIV) flow visualization technique. To do so, a test volume of bubbly flow is globally illuminated with a pulsed light from a continuous wave laser with an acoustic-optic beam chopper, and is observed with four CCD cameras connected to frame grabbers. A digital image of the rising bubble is acquired and analyzed to identify its shape. A reconstruction method, based on the Dynamic Generalized Hough Transform (DGHT), is described that can determine the two-dimensional shape of a bubble from a PIV image.