Settling strongly modifies particle concentrations in wall-bounded turbulent flows even when the settling parameter is asymptotically small

Abstract

Using theory and Direct Numerical simulations, we show that gravitational settling can contribute strongly to particle concentrations in wall-bounded turbulent flows even when the settling number Sv is very small. This occurs because the other competing mechanisms, e.g. the turbophoretic drift velocity, become very small in certain regions of the flow, such as very close to the wall, which we demonstrate using asymptotic analysis.

Topics & Concepts