### Abstract

Original language | English |
---|---|

Pages (from-to) | 465-478 |

Number of pages | 14 |

Journal | Journal of Fluid Mechanics |

Volume | 739 |

Publication status | Published - 2014 |

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### All Science Journal Classification (ASJC) codes

- Condensed Matter Physics
- Mechanical Engineering
- Mechanics of Materials

### Cite this

*Journal of Fluid Mechanics*,

*739*, 465-478.

**Effects of roughness on particle dynamics in turbulent channel flows: a DNS analysis.** / Napoli, Enrico; Milici, Barbara; De Marchis, Mauro; Sardina, Gaetano.

Research output: Contribution to journal › Article

*Journal of Fluid Mechanics*, vol. 739, pp. 465-478.

}

TY - JOUR

T1 - Effects of roughness on particle dynamics in turbulent channel flows: a DNS analysis

AU - Napoli, Enrico

AU - Milici, Barbara

AU - De Marchis, Mauro

AU - Sardina, Gaetano

PY - 2014

Y1 - 2014

N2 - Deposition and resuspension mechanisms in particle-laden turbulent flows are dominated by the coherent structures arising in the wall region. These turbulent structures, which control the turbulent regeneration cycles, are affected by the roughness of the wall. The particle-laden turbulent flow in a channel bounded by irregular two-dimensional rough surfaces is analysed. The behaviour of dilute dispersions of heavy particles is analysed using direct numerical simulations (DNS) to calculate the three-dimensional turbulent flow and Lagrangian tracking to describe the turbophoretic effect associated with two-phase turbulent flows in a complex wallbounded domain. Turbophoresis is investigated in a quantitative way as a function of the particle inertia. The analysis of the particle statistics, in term of mean particle concentration and probability density function (p.d.f.) of wall-normal particle velocity, shows that the wall roughness produces a completely different scenario compared to the classical smooth wall. The effect of the wall roughness on the particle mass flux is shown for six particle populations having different inertia.

AB - Deposition and resuspension mechanisms in particle-laden turbulent flows are dominated by the coherent structures arising in the wall region. These turbulent structures, which control the turbulent regeneration cycles, are affected by the roughness of the wall. The particle-laden turbulent flow in a channel bounded by irregular two-dimensional rough surfaces is analysed. The behaviour of dilute dispersions of heavy particles is analysed using direct numerical simulations (DNS) to calculate the three-dimensional turbulent flow and Lagrangian tracking to describe the turbophoretic effect associated with two-phase turbulent flows in a complex wallbounded domain. Turbophoresis is investigated in a quantitative way as a function of the particle inertia. The analysis of the particle statistics, in term of mean particle concentration and probability density function (p.d.f.) of wall-normal particle velocity, shows that the wall roughness produces a completely different scenario compared to the classical smooth wall. The effect of the wall roughness on the particle mass flux is shown for six particle populations having different inertia.

UR - http://hdl.handle.net/10447/100698

M3 - Article

VL - 739

SP - 465

EP - 478

JO - Journal of Fluid Mechanics

JF - Journal of Fluid Mechanics

SN - 0022-1120

ER -