Analysis of the Adhered Particle Secondary Migration on the Slider Air Bearing Surface

2016 ◽  
Author(s):  
Sen Liu ◽  
Sheng-Nan Shen ◽  
Li Hui ◽  
Fu-Hao Cui
Keyword(s):  
Particle Diameter ◽  
Particle Migration ◽  
Air Bearings ◽  
Particle Movement ◽  
Secondary Migration ◽  
Flow Shear ◽  
Slider Surface ◽  
Slider Air Bearing ◽  
Stationary Action ◽  
And Migration

An entrapped particle on the slider air bearings damages the surface of the slider or the disk. The study of particle movement on and the particle adhesion mechanism onto the slider surface is critical to reduce entrapped particle-induced damage. In this paper, we extend the previous work proposing a dynamical model of the adhesive particle redistribution and migration on the slider surface. The model predicts whether the adhered particle will remain stationary action of the aerodynamic forces. Further, particle behaviors after detachment are analyzed considering the effects of flow shear rate, particle diameter and properties. There are four particle movement styles on the slider surface. Finally, the particle migration trajectory and velocity with time on the slider surface are presented.

The analysis of self-diffusion and migration of rough spheres in nonlinear shear flow using a traction-corrected boundary element method

2008 ◽  
Vol 598 ◽  
pp. 267-292 ◽  
Author(s):  
MARC S. INGBER ◽  
SHIHAI FENG ◽  
ALAN L. GRAHAM ◽  
HOWARD BRENNER
Keyword(s):  
Boundary Element Method ◽  
Shear Flow ◽  
Boundary Element ◽  
Particle Migration ◽  
Self Diffusion ◽  
Centre Of Gravity ◽  
Particle Pairs ◽  
And Migration ◽  
Nonlinear Shear ◽  
Element Method

The phenomena of self-diffusion and migration of rough spheres in nonlinear shear flows are investigated using a new traction-corrected boundary element method (TC-BEM) in which the near-field asymptotics for the traction solution in the interstitial region between two nearly touching spheres is seamlessly coupled with a traditional direct boundary element method. The TC-BEM is extremely accurate in predicting particle trajectories, and hence can be used to calculate both the particle self-diffusivity and a newly defined migration diffusivity for dilute suspensions. The migration diffusivity is a function of a nonlinearity parameter characterizing the shear flow and arises from the net displacement of the centre of gravity of particle pairs. This net displacement of the centre of gravity of particle pairs does not occur for smooth particles, nor for rough particles in a linear shear flow. An explanation is provided for why two-particle interactions of rough spheres in a nonlinear shear flow result in particle migration.

Mechanisms of particle movement in porous media

Clay Minerals ◽  
1986 ◽  
Vol 21 (4) ◽  
pp. 753-767 ◽  
Author(s):  
J. R. Gronow
Keyword(s):  
Pollution Control ◽  
Migration Pattern ◽  
Particle Migration ◽  
Filtration Theory ◽  
Particle Movement ◽  
Factors Affecting ◽  
Activation Products ◽  
Groundwater Systems ◽  
Main Factors ◽  
General Filtration

AbstractActivation products of neutron-irradiated chrysotile and crocidolite which have suitable half-lives have been used as tracers to investigate the attenuation of fibres in media likely to be encountered in groundwater systems. The saturated and unsaturated filtration of chrysotile and crocidolite through columns of beads, gravel and sands is compared. The migration pattern of crocidolite through columns of disturbed and relatively undisturbed Greensand is then compared with the filtration through washed and sieved sand of the same porosity. The main factors affecting the filtration of particles are outlined, and the experimental results obtained are correlated with models used to describe general filtration theory. This is shown to provide a basis from which pollution control models may be derived and indicates that the principles underlying particle filtration will apply to particle migration in any fluid-filled system.

Endothelial cell distributions and migration under conditions of flow shear stress around a stent wire

2019 ◽  
pp. 1-10 ◽  
Author(s):  
Hitomi Anzai ◽  
Tomohito Watanabe ◽  
Xiaobo Han ◽  
Narendra Kurnia Putra ◽  
Zi Wang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Endothelial Cell ◽  
Flow Shear ◽  
Flow Shear Stress ◽  
And Migration

Eromanga (Queensland) exploration–new concepts for an old basin

2011 ◽  
Vol 51 (1) ◽  
pp. 333
Author(s):  
David Lowry ◽  
David Evans
Keyword(s):  
Oil And Gas ◽  
Oil Field ◽  
Secondary Migration ◽  
New Concepts ◽  
Oil Generation ◽  
And Migration ◽  
Oil Expulsion ◽  
Sonic Logs ◽  
Southern Flank ◽  
Eromanga Basin

Eromanga Basin exploration surged in Queensland after the discovery of the Jackson field in 1982, but has ebbed over the last 20 years. Perceived exploration risks are: • Oil generation and migration peaked in the mid-Cretaceous before much of the anticlinal structuring, so that modern structure is an uncertain guide to Cretaceous migration paths. • Permian coals are generally credited with sourcing most of the oil and gas in the Cooper-Eromanga Basin. In Queensland, the Permian largely drains to the southern flank and the northern flank is thought to have a high charge risk. This study covers 100,000 km2. It used sonic logs to determine the amount of Tertiary erosion and thus allows the preparation of structure maps restored to mid-Cretaceous time. Maturity maps of the Birkhead and Poolowanna Formations were computed from a reflectance/restored temperature algorithm based on 50 wells. Source rock thickness maps and an oil expulsion model based on Pepper and Corvi (1995a, 1995b) then allowed oil expulsion to be mapped regionally. The study produces the key results that could be expected from 3D earth modelling, but with great savings in time and money. The study demonstrates an oil kitchen at both Poolowanna and Birkhead stratigraphic levels in the vicinity of Tanbar–1. Secondary migration losses are speculative, but modelling shows that hundreds of millions of barrels of oil from each formation have migrated west towards the Curalle ridge, north to Inland and Morney, and southeast to Mt Howitt. The Inland oil field is presently an isolated anomaly on the northwest flank of the basin, but this study suggests that further exploration in the area could be successful.

FRACTALS AND SECONDARY MIGRATION

Fractals ◽  
1995 ◽  
Vol 03 (04) ◽  
pp. 799-806 ◽  
Author(s):  
PAUL MEAKIN ◽  
GERI WAGNER ◽  
VIDAR FRETTE ◽  
JENS FEDER ◽  
TORSTEIN JØSSANG
Keyword(s):  
Oil And Gas ◽  
Fractal Model ◽  
Source Rocks ◽  
Fracture Aperture ◽  
Low Density ◽  
Secondary Migration ◽  
Gravity Driven ◽  
And Migration ◽  
Water Saturated ◽  
Wetting Fluid

The process of secondary migration, in which oil and gas are transported from the source rocks, through water saturated sedimentary carrier rocks, to a trap or reservoir can be described in terms of the gravity driven penetration of a low-density non-wetting fluid through a porous medium saturated with a wetting fluid. This process has been modeled in the laboratory and by computer simulations using homogeneous porous media. Under these conditions, the pattern formed by the migrating fluid can be described in terms of a string of fractal blobs. The low density internal structure of the fractal blobs and the concentration of the transport process onto the self-affine strings of blobs (migration channels) both contribute to the small effective hydrocarbon saturation in the carrier rocks. This allows the hydrocarbon fluids to penetrate the enormous volume of carrier rock without all of the hydrocarbon being trapped in immobile isolated bubbles. In practice, heterogeneities in the carrier rocks play an important role. In some cases, these heterogeneities can be represented by fractal models and these fractal heterogeneity models provide a basis for more realistic simulations of secondary migration. Fractures may play a particularly important role and migration along open fractures was simulated using a self-affine fractal model for the fluctuating fracture aperture.

A numerical study of particle migration in porous media during produced water reinjection

2021 ◽  
pp. 1-34
Author(s):  
Tian Xia ◽  
Qihong Feng ◽  
Sen Wang ◽  
Qinglin Shu ◽  
Yigen Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Porous Media ◽  
Oil Recovery ◽  
Produced Water ◽  
Numerical Study ◽  
Particle Diameter ◽  
Particle Migration ◽  
Critical Ratio ◽  
Clear Understanding ◽  
The Impact

Abstract The clogging phenomenon often occurs during the reinjection of produced water due to the suspended particles, which will deteriorate the development efficiency. Many experimental and analytical methods have been introduced to solve this problem; however, few numerical approaches have been proposed to investigate the particle migration in the produced water reinjection process. Moreover, it is hard to obtain a clear understanding directly from the particle scale when the injected particles have different sizes. This paper employs a coupled lattice Boltzmann method and discrete element method (LBM-DEM) to study the aforementioned process. The method was validated by reproducing the Drafting-Kissing-Tumbling (DKT) process. Simulations of migration of injected particles with different sizes through porous media were conducted and three clogging scenarios had been identified. We investigated the impact of injected particle size distribution and porous media on particle migration and concluded the results in the polydisperse aspect. From the simulation, we can conclude that mix clogging is the scenario we should try to avoid. Besides, both critical ratio of particle diameter of porous media to median particle diameter of injected particles (D/d50) and critical standard deviation value exist. The particle size range should be as small as possible in economical limits and the D/d50 value should be larger than the critical value. Our results can provide a good guide for the produced water pretreatment, which can improve oil recovery.

scholarly journals Numerical Simulation of Particles Deposition in a Human Upper Airway

2014 ◽  
Vol 6 ◽  
pp. 207938 ◽  
Author(s):  
Debo Li ◽  
Qisheng Xu ◽  
Yaming Liu ◽  
Yin Libao ◽  
Jin Jun
Keyword(s):  
Numerical Simulation ◽  
Nasal Cavity ◽  
Particle Deposition ◽  
Geometric Model ◽  
Particle Diameter ◽  
Upper Airway ◽  
Deposition Efficiency ◽  
Particle Movement ◽  
Scanned Images ◽  
Les Model

Based on the CT scanned images, a realistic geometric model from nasal cavity to upper six-generation bronchia is rebuilt. In order to effectively simulate the particle movement and deposition, LES model is used and the particles are tracked in the frame of Lagrange. Seven kinds of typical particles, including micron particles (1, 5, and 10 μm) and nanoparticles (1, 5, 20, and 100 nm), and three representative respiratory intensities are adopted as computational case, respectively. Deposition efficiency ( D E), deposition concentration ( D C), and capture efficiency ( C E) are introduced. Furthermore, the locations of particle deposition are visualized. The results indicate that the injecting particles from different nasal inlet present “transposition effect.”The D E values of micron particles are much higher than nanoparticles. The particle diameter plays a weaker role in nanoparticle depositions than micron particles. The highest values of D E and D C both occur in nasal cavity, while the highest C E up to 99.5% occurs in bronchus region.

Field Controlled Charge and Heat Transfer Involving Macroscopic Charged Particles in Liquids

1975 ◽  
Vol 97 (3) ◽  
pp. 429-434 ◽  
Author(s):  
P. W. Dietz ◽  
J. R. Melcher
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Charged Particles ◽  
Particle Diameter ◽  
Particle Migration ◽  
Electrically Conducting ◽  
Fluid Convection ◽  
Experimental Values ◽  
Insulating Liquid ◽  
Parallel Electrode

When an electric field is applied to a system of electrically conducting particles in an insulating liquid, the rates of charge and heat transfer are augmented. Charged during collisions in the field, the particles execute field-induced excursions between the electrodes interrupted by collisions with other particles. Thus a combination of particle migration and particle-induced fluid convection results in the increase in heat transfer. Experimental values for the Nusselt number are obtained for heat transfer across the parallel electrode configuration. The model developed using these results consists of a well-mixed central region with thermal boundary layers about one particle diameter thick near each electrode.

Computation of local permeability in granular soils using spatial time domain reflectometer

2022 ◽  
Vol 12 (1) ◽  
pp. 1-26
Author(s):  
V. S. R. Annapareddy ◽  
T. Bore ◽  
M. Bajodek ◽  
A. Scheuermann
Keyword(s):  
Time Domain ◽  
Particle Diameter ◽  
Time Domain Reflectometry ◽  
Particle Migration ◽  
Granular Soils ◽  
Practical Applications ◽  
Effective Particle ◽  
Local Permeability ◽  
Order Of Magnitude ◽  
Time Domain Reflectometer

This letter proposes semi-analytical methods to obtain the local permeability for granular soils based on indirect measurements of the local porosity profile in a large coaxial cell permeameter using spatial time domain reflectometry. The porosity profile is used to obtain the local permeability using the modified Kozeny-Carman and Katz-Thompson equations, which incorporated an effective particle diameter that accounted for particle migration within the permeameter. The profiles of the local permeability obtained from the proposed methods are compared with experimentally obtained permeability distributions using pressure measurements and flow rate. The permeabilities obtained with the proposed methods are comparable with the experimentally obtained permeabilities and are within one order of magnitude deviation, which is an acceptable range for practical applications.

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