Mesoscale flow structures fluid—particle interaction

Mesoscale Flow Structures and Fluid-Particle Interactions... 

These three approaches will now first be discussed in some detail this leads to an intermediate conclusion with respect to the dominating role of fluid-particle interaction in the development of mesoscale structures. On this basis of this conviction, the main body of this chapter will be devoted to fluid-particle interaction in dispersed multiphase flows and a proper description of the forces involved. 

In addition to the attempts to better understand the origin of mesoscale structures in dispersed two-phase flows by means of extremum principles and stabflity analyses, CFD simulations may provide guidance. One may therefore expect that simulations of particle behavior on the basis of a proper description of the fluid—particle interaction force reproduce the formation and dynamics of coherent structures and clusters (see also Capecelatro et al, 2015). After all, CFD simulations allow visualizations of 3D transient flow fields and make it possible to systematically investigate the effect of all types of variables (flow rates, physical properties, geometrical parameters) on flow fields to a degree not feasible experimentally. 

It is the author s conviction that in many (turbulent) dispersed multiphase flows—except probably in very dense multiphase flow systems—the origin of mesoscale structures is in the fluid—particle interaction, with a secondary role for particle-particle interaction (coUisions, coalescence, breakup). Clustering of particles is believed to be intimately connected with the chaotic dynamics of fluid accelerations, as particles converge toward each other where and when the divergence of the acceleration field is positive (Goto... 

Ning Yang, Mesoscale Transport Phenomena and Mechanisms in Gas-Liquid Reaction Systems Harry E.A. Van den Akker, Mesoscale Flow Structures and Fluid—Particle Interactions... 

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