Wake Disappearance and Mean Flow Results for Multibody and Multiphase Flows

Complex multibody and multiphase flow problems represent a significant challenge to describe computationally and to study experimentally. In this paper we describe two main physical processes, which are studied analytically and which have a wide bearing on bubbly flows. The first is the general phenomena of vorticity annihilation which occurs when in the presence of straining motion generated by neighbouring bodies or through wakes intermingling with their neighbours. The second is blocking due to the flow having to go around these bubbles, which is studied using inviscid flow theory. By applying a new methodology, we provide a clear physical argument for drift-flux correlations typically assumed in multiphase models. Finally, we show how the two processes, vorticitiy annihilation and blocking, can be combined within one theoretical model and the consequences for modeling multibody and multiphase flows.