A novel particle tracking and break-up detection algorithm: application to theturbulent break-up of bubbles

Abstract

A new method has been developed to measure experimentally the break-upproperties of bubbles. The technique is based on the application of a particletracking velocimetry algorithm to high-speed video images not only to measurethe velocity of the bubbles, but also to detect the break-up events. Thus thealgorithm is able to associate every broken bubble with the daughter bubblesformed upon their corresponding break-up. Moreover, the lifetime, as well as thenumber and size of fragments resulting from the break-up process, can bemeasured for a large number of bubbles. Statistical processing of the informationcollected allows us to compute the break-up frequency and daughter sizedistribution of the bubbles as a function of the bubble size and the meanproperties of the base flow. The method has been employed to study the break-upof a cloud of bubbles injected at the central axis of a turbulent water jet.Experimental results for the break-up frequency and daughter bubble sizedistribution are also presented to illustrate the performance of the technique.