Large heavy particles in turbulent pipe flows: Skin friction drag, turbulence modulation and preferential particle distribution

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388998%3A_____%2F25%3A00642519" target="_blank" >RIV/61388998:_____/25:00642519 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.aip.org/aip/pof/article-abstract/37/11/113337/3373287/Large-heavy-particles-in-turbulent-pipe-flows-Skin?redirectedFrom=fulltext" target="_blank" >https://pubs.aip.org/aip/pof/article-abstract/37/11/113337/3373287/Large-heavy-particles-in-turbulent-pipe-flows-Skin?redirectedFrom=fulltext</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0292384" target="_blank" >10.1063/5.0292384</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Large heavy particles in turbulent pipe flows: Skin friction drag, turbulence modulation and preferential particle distribution

Popis výsledku v původním jazyce

Previous studies on particle-laden flows have focused mainly on either small, heavy particles or large, and weakly buoyant particles. We present measurements in the regime of large and heavy particles, investigating the particle-turbulence dynamics over a parameter space covering a wide range of particle volume fractions, Stokes and Froude numbers at low to moderate Reynolds numbers. We consider the flow in a vertical pipe, thus allowing for the investigation of the two-way coupling between particles and the carrier phase turbulence while excluding the effect of gravity-induced settling on the wall-normal migration of particles. Pressure drop measurements indicate a linear increase in the skin friction coefficient with the volume fraction of particles. The growth rate of the skin friction coefficient was found to scale inversely with the Froude number. Using time-resolved particle image velocimetry measurements, we show that the carrier phase turbulence is modulated even at particle concentrations as low as 0.3%, indicating that particle-induced stresses due to the distortion of fluid streamlines cannot be neglected. Additionally, using Voronoi tessellations to quantify the particle concentration field, we observe a strong deviation from the Poisson behavior for cases both with and without turbophoresis. The results of particle tracking show that the particles move in roughly straight-line trajectories, which deviate from the flow streamlines with a mean angle of about 2 degrees and a maximum angle of about 9 degrees. The particles were also observed to be situated away from vortex cores indicating the occurrence of the centrifuge mechanism.

Název v anglickém jazyce

Large heavy particles in turbulent pipe flows: Skin friction drag, turbulence modulation and preferential particle distribution

Popis výsledku anglicky

Previous studies on particle-laden flows have focused mainly on either small, heavy particles or large, and weakly buoyant particles. We present measurements in the regime of large and heavy particles, investigating the particle-turbulence dynamics over a parameter space covering a wide range of particle volume fractions, Stokes and Froude numbers at low to moderate Reynolds numbers. We consider the flow in a vertical pipe, thus allowing for the investigation of the two-way coupling between particles and the carrier phase turbulence while excluding the effect of gravity-induced settling on the wall-normal migration of particles. Pressure drop measurements indicate a linear increase in the skin friction coefficient with the volume fraction of particles. The growth rate of the skin friction coefficient was found to scale inversely with the Froude number. Using time-resolved particle image velocimetry measurements, we show that the carrier phase turbulence is modulated even at particle concentrations as low as 0.3%, indicating that particle-induced stresses due to the distortion of fluid streamlines cannot be neglected. Additionally, using Voronoi tessellations to quantify the particle concentration field, we observe a strong deviation from the Poisson behavior for cases both with and without turbophoresis. The results of particle tracking show that the particles move in roughly straight-line trajectories, which deviate from the flow streamlines with a mean angle of about 2 degrees and a maximum angle of about 9 degrees. The particles were also observed to be situated away from vortex cores indicating the occurrence of the centrifuge mechanism.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physics of Fluids

ISSN

1070-6631

e-ISSN

1089-7666

Svazek periodika

37

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

27

Strana od-do

113337

Kód UT WoS článku

001624283000012

EID výsledku v databázi Scopus

2-s2.0-105022792743