The Role of Entrapment Phenomena in the Modification of a Plane Mixing Layer by Bubbles

Abstract

Understanding the interactions occurring between clouds of bubbles (or solid particles) and turbulent flows represents a key step in the development of models required for predicting turbulent dispersed flows encountered in engineering or in oceanography. Such interactions are currently divided into two sets. The first one is simply the dispersion of bubbles due to the motion of the continuous phase. This kind of interactions (one-way coupling) has been widely studied in various flow configurations. The second sort of interactions (two-way coupling) is related to the modifications induced by the dispersed phase on the structure of the surrounding turbulent flow. Such interactions are much more difficult to study because they result basically from an inverse-cascade process, since bubbles of small size may affect the whole range of scales of the flow and may even in certain cases drive the largest scales. In some recent attempts, two-way coupling effects were studied by forcing the Navier-Stokes equations by source terms representing the influence of the dispersed phase. In the present study we use the same kind of methodology in order to examine how a plane upflowing mixing layer is modified by a large number of bubbles and how the dispersion of these bubbles is affected by the interaction process.KeywordsDisperse PhaseSpreading RateLarge BubbleBubble DiameterStable Fixed PointThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.