A Computational Study on the correlation between flow characteristics and particle deposition*

The complexity of the mechanism of particle dispersion and deposition in wall-bounded turbulent flows is a fundamental issue and it is crucial to get familiar with different aspects of it. Therefore, understanding of this phenomenon could help reduce its negative economical and environmental effects.

In this work, we explore the effect of flow (carrier phase) characteristics on small particle dispersion and deposition in a fully developed turbulent channel flow. Towards this, we carry out point particle-direct numerical simulations (PP--DNS), at  two friction Reynolds numbers: Re_τ=180 and Re_τ=1000 ,and assume one-way coupling .

We aim to demonstrate that different fluid flow characteristics could lead to different particle deposition rates even for the same particle size and, the Stokes number alone (the dimensionless particle relaxation time) does not completely capture the dynamics of particle dispersion and deposition. Additionally, we investigate the interplay between gravity and Reynolds number and show that effects of gravity are only negligible at high Reynolds numbers. Otherwise, the zero-gravity studies cannot be extended to non-zero gravity systems.