(70dj) Simulation of Solid Particles Behaviour in a Driven Cavity Flow

The paper focuses on simulation of driven flow in a cavity containing an incompressible fluid and solid particles. The particle phase will be modelled using the Eulerian-Lagrangian (E-L) approach where the solid particles are treated as points moving in the computational domain as a result of the fluid motion. In the mathematical model, the particle-particle interactions are simulated using the hard-sphere model. Different cases will be considered, where the Reynolds number of the flow (defined by the velocity of the moving boundary, size of the cavity and fluid viscosity) and particle momentum response time will vary. The main objective of this work is to analyze the onset of particle agglomerate formation of particles under the action of the flow. This issue has various applications, for example in pneumatic transport of dusts. The results will be shown as snapshots of particle location at specific points in time, as well as statistics to characterize the behaviour in the dust cloud. Both one- and two-way coupling will be considered making it possible to determine the influence of the particle cloud on the gas phase in a driven cavity flow. The main conclusion from our observation is that some particles gather into agglomerate-like assemblies. These agglomerates last for certain time, whereafter they are broken due to shear stresses in the fluid flow. These phenomena are dependent on the collision restitution coefficient: a low value facilitates the formation of such assemblies significantly. Another aspect that will be described in the paper is the influence of the initial particle distribution. During the simulation, the computation process is started for a pure fluid only (without particles). After some time, the fluid flow becomes steady and then the particles are introduced. Their initial distribution can be uniform, where they are located at equal distances to each other, or at random.