  Particle-laden turbulent flow that separates due to a bump inside a channel
is simulated to analyse the effects of the Stokes number and the lift force on
the particle spatial distribution. The fluid friction Reynolds number is
approximately 900 over the bump, the highest achieved for similar computational
domains. A range of particle Stokes numbers are considered, each simulated with
and without the lift force in the particle dynamic equation. When the lift
force is included a significant difference in the particle concentration, in
the order of thousands, is observed in comparison with cases where the lift
force is omitted. The greatest deviation is in regions of high vorticity,
particularly at the walls and in the shear layer but results show that the
concentration also changes in the bulk of the flow away from the walls. The
particle behaviour changes drastically when the Stokes number is varied. As the
Stokes number increases, particles bypass the recirculating region that is
formed after the bump and their redistribution is mostly affected by the strong
shear layer. Particles segregate at the walls and particularly accumulate in
secondary recirculating regions behind the bump. At higher Stokes numbers, the
particles create reflection layers of high concentration due to their inertia
as they are diverted by the bump. The fluid flow is less influential and this
enables the particles to enter the recirculating region by rebounding off walls
and create a focus of high particle concentration.
