LES-DPS of the effect of wall roughness on dispersed-phase transport in particle-laden turbulent channel flow

Kyle Squires, Olivier Simonin

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

The influence of wall roughness on dispersed-phase properties of particle-laden turbulent channel flow is investigated using large eddy simulation (LES) for the fluid flow and discrete particle simulation (DPS) for the particulate phase. Gas-solid flows are considered for which the particle equation of motion includes the contribution from the drag force. The influence of wall roughness is treated stochastically in which the impact angle is comprised of the particle trajectory angle and a stochastic component due to wall roughness. Elastic particle-wall collisions are considered with surface roughness characterized in terms of the standard deviation of the distribution of wall roughness angles. Computations are performed for three Stokes numbers and standard deviations in the wall roughness angle of 0 (smooth wall), 2.5° and 5°. LES-DPS results show that for a given wall roughness angle and particle Stokes number the most pronounced effect is on the wall-normal component of the particle velocity, which can be substantially increased by roughness. While the streamwise particle velocity variance also increases, the spanwise particle fluctuating velocity exhibits relatively little sensitivity to surface roughness. In addition, LES/DPS results show that wall roughness increases turbulent transport of the wall-normal particle velocity variance, in turn providing a mechanism for elevation of the particle velocity fluctuations across the entire flow.

Original languageEnglish (US)
Pages (from-to)619-626
Number of pages8
JournalInternational Journal of Heat and Fluid Flow
Volume27
Issue number4
DOIs
StatePublished - Aug 2006

Fingerprint

Large eddy simulation
large eddy simulation
channel flow
Channel flow
roughness
Surface roughness
simulation
standard deviation
surface roughness
Flow of solids
solids flow
particle trajectories
Equations of motion
Drag
Flow of fluids
particulates
Gases
drag
fluid flow
Trajectories

Keywords

  • Particle-laden turbulent flow
  • Wall roughness

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes
  • Mechanical Engineering

Cite this

LES-DPS of the effect of wall roughness on dispersed-phase transport in particle-laden turbulent channel flow. / Squires, Kyle; Simonin, Olivier.

In: International Journal of Heat and Fluid Flow, Vol. 27, No. 4, 08.2006, p. 619-626.

Research output: Contribution to journalArticle

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