Characterisation of bubble clusters in simulations of upward turbulent channel flow

Abstract

The paper reports on Direct Numerical Simulations of bubble‐laden flows performed to investigate the interaction of bubbles with turbulence in an upward flow between two parallel vertical plates. Two simulations are presented with uniform bubble diameter and a third one with bi‐disperse bubbles. Three different approaches are used to characterize bubble clustering in the investigated configuration. Horizontal pairing and tendency to form cluster has been found for all reported cases, slightly less pronounced in the bi‐disperse swarm. Among other results, a 60°‐alignment has been found by means of the angular pair correlation function for the mixed pairs in the bi‐disperse swarm. (© 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)