The effect of turbulence on the particle impaction on a cylinder in a cross flow

TL;DR

This study uses DNS to explore how different turbulence scales affect particle impaction on a cylinder in cross flow, revealing significant impacts on impaction efficiency depending on particle Stokes number and turbulence scale.

Contribution

It provides new insights into how isotropic homogeneous turbulence with varying integral scales influences particle impaction efficiency on cylinders in cross flow.

Findings

Large integral scale turbulence increases front side impaction up to 10 times compared to laminar flow.

Decreasing integral scales reduce the turbulence effect on front side impaction.

Back side impaction efficiency is maximized at small integral scales.

Abstract

Particle impaction on a cylinder in a cross flow is investigated with the use of Direct Numerical Simulations (DNS) and with a focus on the effect of turbulence on the impaction efficiency. The turbulence considered is isotropic homogeneous turbulence with varying integral scales. It is found that for particles with Stokes numbers in the boundary stopping mode there is up to 10 times more front side impaction for turbulence with a large integral scale than for a corresponding laminar flow. For decreasing integral scales the effect of the turbulence on front side particle impaction efficiency is decreasing. The back side impaction efficiency is also found to be influenced by the turbulence, but for the back side the strongest effect, and largest impaction efficiency, is found for small integral scales.