A generalized particle-to-wall collision model for non-spherical rigid particles

Fouling mechanisms and models for flux decline are investigated with a three-dimensional simulation of the tortuous, verisimilar geometry of an α-alumina microfilter. Reconstruction of the three-dimensional geometry was accomplished from two-dimensional cross-sectional cuts. A wall collision model and a particle trapping model are developed for the investigation of fouling mechanisms. The reconstructed geometry and the two models were used in computational fluid dynamics to simulate metalworking colloidal particles travelling through and becoming trapped in the tortuous pore paths of a microfilter. Results reveal sharp flux decline initiating from partial pore blocking and subdued flux decline transitioning to cake layer development with steady-state flow. This flow behavior is in agreement with experimental data from earlier studies. The inclusion of the wall collision model and particle trapping model enabled the revelation of cake layer development as a fouling mechanism. Additional simulations of microfilters at different particle size distributions were conducted and discussed.

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Three-Dimensional Simulation of Cross-Flow Microfilter Fouling in Tortuous Pore Profiles With Semi-Synthetic Metalworking Fluids

ASME 2010 International Manufacturing Science and Engineering Conference, Volume 2 ◽

10.1115/msec2010-34269 ◽

2010 ◽

Cited By ~ 2

Author(s):

Bingyi Yu ◽

Shiv G. Kapoor ◽

Richard E. DeVor

Keyword(s):

Colloidal Particles ◽

Three Dimensional ◽

Particle Trapping ◽

Collision Model ◽

Flux Decline ◽

Cake Layer ◽

Trapping Model ◽

Wall Collision ◽

Dimensional Simulation ◽

Layer Development

Fluid flow and fouling mechanisms are examined with a three-dimensional simulation of the tortuous, verisimilar geometry of an α-alumina microfilter. Reconstruction of the three-dimensional geometry was accomplished from two-dimensional cross-sectional cuts, obtained from a focused ion beam. A wall collision model and a particle trapping model are developed for the investigation of fouling mechanisms. The reconstructed geometry and the two models were used in computational fluid dynamics to simulate metalworking colloidal particles travelling through and trapping in the tortuous pore paths of a microfilter. Results reveal sharp flux decline initiating from partial pore blocking and subdued flux decline finalizing in cake layer development with steady-state flow. This flow behavior is in agreement with experimental data from earlier studies. The inclusion of the wall collision model and particle trapping model enabled the revelation of cake layer development as a fouling mechanism.

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Extension of the hard-sphere particle-wall collision model to account for particle deposition

Physical Review E ◽

10.1103/physreve.79.061302 ◽

2009 ◽

Vol 79 (6) ◽

Cited By ~ 20

Author(s):

Pawel Kosinski ◽

Alex C. Hoffmann

Keyword(s):

Hard Sphere ◽

Particle Deposition ◽

Collision Model ◽

Wall Collision

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Investigating the n=1 and n=2 error fields in W7-X using the newly accelerated FIELDLINES code

Plasma Physics and Controlled Fusion ◽

10.1088/1361-6587/ac43ef ◽

2021 ◽

Author(s):

Dion Engels ◽

Samuel A Lazerson ◽

Victor Bykov ◽

Josefine H E Proll

Keyword(s):

Magnetic Field ◽

Heat Flux ◽

Collision Model ◽

Fusion Device ◽

Load Asymmetry ◽

Wall Collision ◽

Error Field ◽

Line Diffusion ◽

And Control ◽

The Magnetic Field

Abstract No fusion device can be created without any uncertainty; there is always a slight deviation from the geometric specification. These deviations can add up create a deviation of the magnetic ﬁeld. This deviation is known as the (magnetic) error ﬁeld. Correcting these error ﬁelds is desired as they cause asymmetries in the divertor loads and can thus cause damage to the device if they grow too large. These error ﬁelds can be deﬁned by their toroidal (n) and poloidal number (m). The correction of the n = 1 and n = 2 ﬁelds in Wendelstein 7-X (W7-X) is investigated in this work. This investigation focuses on ﬁeld line diﬀusion to the divertor, a proxy for divertor heat ﬂux. Such work leverages the 25x speedup obtained through the implementation of a new particle-wall collision model. The n = 1 and n = 2 error ﬁelds of the as-built coils model of W7-X are corrected by scanning phase and amplitude of the trim and control coils. Reductions in the divertor load asymmetry by factors of four are demonstrated using error ﬁeld correction. It is found that the as-built coils model has a signiﬁcantly lower m⁄n = 1⁄1 error ﬁeld than found in experiments.

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Simulation of Gas-Particle Channel Flows Using a Two-Fluid Particle-Wall Collision Model Accounting for Wall Roughness

Volume 1: Fora, Parts A, B, C, and D ◽

10.1115/fedsm2003-45750 ◽

2003 ◽

Cited By ~ 4

Author(s):

X. Zhang ◽

L. X. Zhou

Keyword(s):

Kinetic Energy ◽

Channel Flows ◽

Fluid Particle ◽

Wall Friction ◽

Wall Roughness ◽

Reynolds Stresses ◽

Collision Model ◽

Wall Collision ◽

Pdpa Measurement ◽

Two Fluid

A two-fluid particle-wall collision model accounting for wall roughness is proposed. It accounts for the effects of wall friction, restitution, in particular the wall roughness, and hence the redistribution of particle Reynolds stresses in different directions at the wall, the absorption of turbulent kinetic energy from the kinetic energy of mean motion at the wall and the attenuation of particle motion by the wall. It gives the effect of wall roughness on the particle turbulence. The proposed model is applied to simulate gas-particle horizontal channel flows and is validated using PDPA measurement results. It is shown that presently used zero-gradient boundary conditions and other collision models of particle phase might give false results.

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