Direct numerical simulation of particle wall transfer and deposition in upward turbulent pipe flow

Marchioli, Cristian; Giusti, Andrea; Salvetti, Maria Vittoria; Soldati, Alfredo

doi:10.1016/s0301-9322(03)00036-3

Cited by 120 publications

(68 citation statements)

References 34 publications

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“…This phenomenon is called turbophoresis and leads to the accumulation of particles near the walls, which has been measured 28 and numerically predicted in DNS of turbulent channel and pipe flow. 3,4 This particle transport mechanism is caused by the inhomogeneity of the turbulent velocity fluctuations 29,30 and can be understood mathematically from the following perturbation expansion of ͑8͒ in case the particle relaxation time is small.…”

Section: Mean Wall-normal Particle Velocitymentioning

confidence: 99%

“…Direct numerical simulations ͑DNS͒ of particle-laden turbulent flows in simple geometries, such as pipe flow and channel flow, have been carried out in this way. [3][4][5] For single-phase flows, large-eddy simulation ͑LES͒ has gradually become a more and more powerful tool, which produces acceptable results with much less computational effort compared to DNS. The development of more accurate subgrid modeling strategies, such as dynamic modeling, 6 approximate deconvolution models, 7 the variational multiscale model, 8,9 and the regularization principle, 10 have demonstrated the large potential of LES for various single-phase turbulent flows.…”

Section: Introductionmentioning

confidence: 99%

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Subgrid modeling in particle-laden channel flow

2006

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Direct numerical simulation ͑DNS͒ and large-eddy simulation ͑LES͒ of particle-laden turbulent channel flow, in which the particles experience a drag force, are investigated for two subgrid models and several Reynolds and Stokes numbers. In this flow, turbophoresis leads to an accumulation of particles near the walls. The objectives of the work are to investigate the accuracy of the subgrid models studied with respect to particle behavior and to explain the observed particle behavior predicted by the different models. The focus is on particle dispersion and mean particle motion in the direction normal to the walls of the channel. For a low Reynolds number, it is shown that the turbophoresis and particle velocity fluctuations are reduced compared to DNS, if the filtered fluid velocity calculated in the LES is used in the particle equation of motion. This is a combined effect of the disregard of the subgrid scales in the fluid velocity and the inadequacy of the subgrid model. Better agreement with DNS is obtained if an inverse filtering model, which was recently proposed, is incorporated into the particle equation. This model is shown to enhance turbophoresis and particle velocity fluctuations in actual LES. The results of the approximate deconvolution model ͑ADM͒ agree better with DNS results than results of the dynamic eddy-viscosity model. This can be explained from the better prediction of the fluid velocity statistics by ADM and the better correspondence of the subgrid models adopted in the fluid and particle equations. Although the differences between the two subgrid models become smaller, similar conclusions are obtained at a higher Reynolds number. Compared to fourth-order interpolation of the fluid velocity to the particle position, second-order interpolation approximately cancels the effect of the subgrid model in the particle equation of motion.

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Section: Mean Wall-normal Particle Velocitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Subgrid modeling in particle-laden channel flow

2006

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“…1,2 This phenomenon has been measured in, e.g., vertical turbulent pipe flow 3 and calculated by direct numerical simulation (DNS) in vertical turbulent pipe and channel flow. 4,5 In these numerical simulations the fluid is modeled as a continuous phase, while for each particle an equation of motion is imposed. The combined effect of drag force on a particle and inertia leads to turbophoresis.…”

mentioning

confidence: 99%

Can turbophoresis be predicted by large-eddy simulation?

Kuerten

Vreman²

2004

Physics of Fluids

110

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Direct numerical simulation (DNS) and large-eddy simulation (LES) of particle-laden turbulent channel flow, in which the particles experience a drag force, are performed. In this flow turbophoresis leads to an accumulation of particles near the walls. It is shown that the turbophoresis in LES is reduced, in case the subgrid effects in the particle equations of motion are ignored. To alleviate this problem an inverse filtering model is proposed and incorporated into the particle equations. The model is shown to enhance the turbophoresis in actual LES, such that a good agreement with the DNS prediction is obtained.

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“…In the case of homogeneous turbulence [3,4,5,11], the particle concentration field will be characterized by local particle accumulation in low-vorticity, high-strain regions. In the case of non-homogeneous turbulence [9,10], the local interaction between particles and turbulence structures produce a remarkably macroscopic behavior leading to long-term particle accumulation in the viscous sublayer [12,13,14]. When particles segregate in specific flow regions, the dilute flow assumption is no longer valid locally.…”

Section: Introductionmentioning

confidence: 99%

Turbulence Modulation by Micro-Particles in Boundary Layers

Picciotto

Giusti

Marchioli

et al.

Fluid Mechanics and Its Applications

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Summary. Turbulent dispersed flows over boundary layers are crucial in a number of industrial and environmental applications. In most applications, the key information is the spatial distribution of inertial particles, which is known to be highly non-homogeneous and may exhibit a complex pattern driven by the structures of the turbulent flow field. Theoretical and experimental evidence shows that fluid motions in turbulent boundary layers are intermittent and have a strongly organized and coherent nature represented by the large scale structures. These structures control the transport of the dispersed species in such a way that the overall distribution will resemble not at all those given by methods in which these motions are ignored.In this paper, we study from a statistical viewpoint turbulence modulation produced by different-size dispersed particles and we examine how particle wall accumulation is modified due to the action of particles themselves in modulating turbulence. The physical mechanisms and the statistics proposed are based on Direct Numerical Simulation of turbulence and Lagrangian particle tracking, considering a two-way coupling between particles and fluid.

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Direct numerical simulation of particle wall transfer and deposition in upward turbulent pipe flow

Cited by 120 publications

References 34 publications

Subgrid modeling in particle-laden channel flow

Subgrid modeling in particle-laden channel flow

Can turbophoresis be predicted by large-eddy simulation?

Turbulence Modulation by Micro-Particles in Boundary Layers

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