Mechanisms governing the settling velocities and spatial distributions of inertial particles in wall-bounded turbulence

We show that as inertial particles settle through a turbulent boundary layer, the mechanism responsible for enhancing their settling rate relative to the Stokes velocity transitions from being the preferential sweeping mechanism to the turbophoretic drift mechanism. We consider the corresponding effect on the particle concentration profiles and discuss how the Rouse model must be modified to account for particle inertia.