Stokesian Dynamics Simulations of Ferromagnetic Colloidal Dispersions Subjected to a Sinusoidal Shear Flow

2000 ◽  
Vol 231 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Akira Satoh ◽  
Geoff N. Coverdale ◽  
Roy W. Chantrell
Keyword(s):  
Shear Flow ◽  
Colloidal Dispersions ◽  
Stokesian Dynamics ◽  
Dynamics Simulations

Stokesian Dynamics Simulations of Ferromagnetic Colloidal Dispersions in a Simple Shear Flow

1998 ◽  
Vol 203 (2) ◽  
pp. 233-248 ◽  
Author(s):  
Akira Satoh ◽  
Roy W. Chantrell ◽  
Geoff N. Coverdale ◽  
Shin-ichi Kamiyama
Keyword(s):  
Shear Flow ◽  
Simple Shear ◽  
Colloidal Dispersions ◽  
Simple Shear Flow ◽  
Stokesian Dynamics ◽  
Dynamics Simulations

Macroscopic Modeling of Viscous Suspension Flows

1994 ◽  
Vol 47 (6S) ◽  
pp. S229-S235 ◽  
Author(s):  
John F. Brady
Keyword(s):  
Shear Flow ◽  
Channel Flow ◽  
Particle Migration ◽  
Balance Model ◽  
Stokesian Dynamics ◽  
Suspension Flows ◽  
Macroscopic Modeling ◽  
Mean Motion ◽  
Dynamics Simulations ◽  
Pressure Driven

Shear-induced particle migration in viscous suspension flows is shown to lead to intrinsic concentration variations in inhomogeneous shear flow. A recently proposed suspension balance model is discussed that explains this migration as resulting from the requirement that the macroscopic suspension pressure be constant perpendicular to the direction of mean motion. The results of this model are shown to compare well with Stokesian Dynamics simulations of pressure-driven channel flow.

Rheological evaluation of colloidal dispersions using the smoothed profile method: formulation and applications

2016 ◽  
Vol 792 ◽  
pp. 590-619 ◽  
Author(s):  
John J. Molina ◽  
Kotaro Otomura ◽  
Hayato Shiba ◽  
Hideki Kobayashi ◽  
Masaki Sano ◽  
...  
Keyword(s):  
Shear Flow ◽  
Rheological Behaviour ◽  
Direct Calculation ◽  
Simulation Method ◽  
Colloidal Dispersions ◽  
Spherical Particles ◽  
Shear Stresses ◽  
Stokesian Dynamics ◽  
Profile Method ◽  
Smoothed Profile Method

The smoothed profile method is extended to study the rheological behaviour of colloidal dispersions under shear flow by using the Lees–Edwards boundary conditions. We start with a reformulation of the smoothed profile method, a direct numerical simulation method for colloidal dispersions, so that it can be used with the Lees–Edwards boundary condition, under steady or oscillatory-shear flow. By this reformulation, all the resultant physical quantities, including local and total shear stresses, become available through direct calculation. Three simple rheological simulations are then performed for (1) a spherical particle, (2) a rigid bead chain and (3) a collision of two spherical particles under shear flow. Quantitative validity of these simulations is examined by comparing the viscosity with that obtained from theory and Stokesian dynamics calculations. Finally, we consider the shear-thinning behaviour of concentrated colloidal dispersions.

Normal stresses and microstructure in bounded sheared suspensions via Stokesian Dynamics simulations

2000 ◽  
Vol 412 ◽  
pp. 279-301 ◽  
Author(s):  
ANUGRAH SINGH ◽  
PRABHU R. NOTT
Keyword(s):  
Normal Stress ◽  
Couette Flow ◽  
Normal Stress Difference ◽  
Stress Difference ◽  
Normal Stresses ◽  
Plane Couette Flow ◽  
Stokesian Dynamics ◽  
First Normal Stress Difference ◽  
Particle Pressure ◽  
Dynamics Simulations

We report the normal stresses in a non-Brownian suspension in plane Couette flow determined from Stokesian Dynamics simulations. The presence of normal stresses that are linear in the shear rate in a viscometric flow indicates a non-Newtonian character of the suspension, which is otherwise Newtonian. While in itself of interest, this phenomenon is also important because it is believed that normal stresses determine the migration of particles in flows with inhomogeneous shear fields. We simulate plane Couette flow by placing a layer of clear fluid adjacent to one wall in the master cell, which is then replicated periodically. From a combination of the traceless hydrodynamic stresslet on the suspended particles, the stresslet due to (non-hydrodynamic) inter-particle forces, and the total normal force on the walls, we determine the hydrodynamic and inter-particle force contributions to the isotropic ‘particle pressure’ and the first normal stress difference. We determine the stresses for a range of the particle concentration and the Couette gap. The particle pressure and the first normal stress difference exhibit a monotonic increase with the mean particle volume fraction ϕ. The ratio of normal to shear stresses on the walls also increases with ϕ, substantiating the result of Nott & Brady (1994) that this condition is required for stability to concentration fluctuations. We also study the microstructure by extracting the pair distribution function from our simulations; our results are in agreement with previous studies showing anisotropy in the pair distribution, which is the cause of normal stresses.

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