Suspension Mechanism of Small Heavy Particles in a Horizontal Turbulent Boundary Layer Flow, Pipe Flow or Channel Flow

摘要

Developments of Lumley's mixing length model for the heavy particle suspension mechanism are summarized. Lumley's model is only valid in the constant stress layer, not in the viscous sublayer and generation layer. Experimental results show that in the latter regions deposition occurs in downsweeps, whereas particle detachment and reentrainment are caused by ejections. Predictions of a model for the heavy particle suspension mechanism in the viscous sublayer and generation layer based on the existence of such flow phenomena are confirmed by experimental data. In this model there is no influence of the particles on the turbulent flow.