Mechanism of Particle Transport in a Fully Developed Wake Flow

In this paper, the time-dependent Navier–Stokes equations were integrated in time using a mixed explicit-implicit operator splitting rules. The spatial discretization was processed using the spectral-element method. Nonreflecting conditions were employed at the outflow boundary. Particles were traced by the Lagrangian approach based on one-way coupling between the continuous and the disperse phases. The simulation results of the flow field agree well with experimental data. Particles (St = 4) are found to concentrate in the regions between adjacent vortex structures (RAVS) together with other particles dispersed outside of vortex outlining the boundaries of the large-scale vortex structures, which is independent of the flow Reynolds number. Due to U-velocity component difference, at the entrance of RAVS the flow does “compact” on particles causing particle concentration, and it increases with the flow Reynolds number and particle size. The mechanism of particle transport in the wake flow mostly depends on the strong interactions between two alternative and successive shedding vortex structures with opposite sign. Particle transport in the wake flow could be briefly described as follows: moving around vortices and going ahead with vortices.