Hydrodynamic particle removal from surfaces

Burdick, G. M.; Berman, Neil S.; Beaudoin, Stephen P.

doi:10.1016/j.tsf.2005.04.112

Cited by 113 publications

(97 citation statements)

References 17 publications

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“…In the formulation of remobilization conditions, due to the static nature of the problem, we can greatly benefit from the use of force diagrams. Very similar force diagrams are encountered in the field of aerosol science in industrial problems related to the hydrodynamic removal of contaminant dust [44][45][46]. The main difference is that remobilization in those cases is induced by strong laminar or turbulent gas flows and not by plasma.…”

Section: Force Diagram For a Dust Grain In Contact With The Pfcmentioning

confidence: 74%

Dust remobilization in fusion plasmas under steady state conditions

Tolias

Ratynskaia

Angeli

et al. 2016

Plasma Phys. Control. Fusion

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The first combined experimental and theoretical studies of dust remobilization by plasma forces are reported. The main theoretical aspects of remobilization in fusion devices under steady state conditions are analyzed. In particular, the dominant role of adhesive forces is highlighted and generic remobilization conditions -direct lift-up, sliding, rolling -are formulated. A novel experimental technique is proposed, based on controlled adhesion of dust grains on tungsten samples combined with detailed mapping of the dust deposition profile prior and post plasma exposure. Proof-ofprinciple experiments in the TEXTOR tokamak and the EXTRAP-T2R reversed-field pinch are presented. The versatile environment of the linear device Pilot-PSI allowed for experiments with different magnetic field topologies and varying plasma conditions that were complemented with camera observations.

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Section: Force Diagram For a Dust Grain In Contact With The Pfcmentioning

confidence: 74%

Dust remobilization in fusion plasmas under steady state conditions

Tolias

Ratynskaia

Angeli

et al. 2016

Plasma Phys. Control. Fusion

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“…Furthermore, the applied hydrodynamic torque increases with the cube of the colloid radius, and also increases in finer textured media (Torkzaban et al, 2007). Larger scale roughness locations and grain-grain contact points will dramatically increase the resisting adhesive torque and decrease the applied hydrodynamic torque at these locations in comparison to smooth surfaces Burdick et al, 2005). Both of these factors will tend to diminish the role of q w on release.…”

Section: Amount Of Transient Colloid Releasementioning

confidence: 99%

Equilibrium and kinetic models for colloid release under transient solution chemistry conditions

Bradford

Torkzaban

Leij

et al. 2015

Journal of Contaminant Hydrology

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We present continuum models to describe colloid release in the subsurface during transient physicochemical conditions. Our modeling approach relates the amount of colloid release to changes in the fraction of the solid surface area that contributes to retention. Equilibrium, kinetic, equilibrium and kinetic, and two-site kinetic models were developed to describe various rates of colloid release. These models were subsequently applied to experimental colloid release datasets to investigate the influence of variations in ionic strength (IS), pH, cation exchange, colloid size, and water velocity on release. Various combinations of equilibrium and/or kinetic release models were needed to describe the experimental data depending on the transient conditions and colloid type. Release of Escherichia coli D21g was promoted by a decrease in solution IS and an increase in pH, similar to expected trends for a reduction in the secondary minimum and nanoscale chemical heterogeneity. The retention and release of 20 nm carboxyl modified latex nanoparticles (NPs) were demonstrated to be more sensitive to the presence of Ca 2+ than D21g. Specifically, retention of NPs was greater than D21g in the presence of 2 mM CaCl 2 solution, and release of NPs only occurred after exchange of Ca 2+ by Na + and then a reduction in the solution IS. These findings highlight the limitations of conventional interaction energy calculations to describe colloid retention and release, and point to the need to consider other interactions (e.g., Born, steric, and/ or hydration forces) and/or nanoscale heterogeneity. Temporal changes in the water velocity did not have a large influence on the release of D21g for the examined conditions. This insensitivity was likely due to factors that reduce the applied hydrodynamic torque and/or increase the resisting adhesive torque; e.g., macroscopic roughness and grain-grain contacts. Our analysis and models improve our understanding and ability to describe the amounts and rates of colloid release and indicate that episodic colloid transport is expected under transient physicochemical conditions. Published by Elsevier B.V.

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“…Several studies have been conducted on particle removal in which authors experimentally validated hydrodynamic force balances models for particle removal [16][17][18]. Generally, the major challenge in such force balances is the prediction of the adhesive force between the particle and the substrate.…”

Section: Introductionmentioning

confidence: 99%