Wall Effects On the Flow Dynamics of a Rigid Sphere in Motion

2021 ◽  
Author(s):  
Zhi-gang Feng ◽  
Jason Gatewood ◽  
E.E. Michaelides
Keyword(s):  
Hydrodynamic Force ◽  
Rotational Velocity ◽  
Analytical Data ◽  
Particle Diameter ◽  
Immersed Boundary ◽  
Rigid Sphere ◽  
Wall Effects ◽  
Falling Sphere ◽  
Dimensionless Ratio ◽  
Free Falling

Abstract The presence of a wall near a rigid sphere in motion is known to disturb the particle fore and aft flow field symmetry and to affect the hydrodynamic force. An Immersed Boundary Direct Numerical Simulation (IB-DNS) is used in this study to determine the wall effects on the dynamics of a free-falling sphere and the drag of a sphere moving at a constant velocity. The numerical results are validated by comparison to the published experimental, numerical, and analytical data. The pressure and velocity fields are numerically computed when the particle is in the vicinity of the wall; the transverse (lift) and longitudinal (drag) parts of the hydrodynamic force are calculated; its rotational velocity is also investigated in the case of a free-falling sphere. The flow asymmetry also causes the particle to rotate. The wall effect is shown to be significant when the dimensionless ratio of the wall distance to the particle diameter, L/D, is less than 3. The wall effects are more pronounced and when the particle Reynolds number, Re, is less than 10. Based on the computational results, a useful correlation for the wall effects on the drag coefficients spheres is derived in the range 0.75 < L/D < 3 and 0.18 < Re < 10.

An Immersed Boundary Direct Numerical Simulation Study of the Wall Effect on the Dynamics of a Rigid Sphere

2017 ◽  
Author(s):  
Jason Gatewood ◽  
Zhi-Gang Feng
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Direct Numerical Simulation ◽  
Drag Coefficient ◽  
Particle Diameter ◽  
Laminar Flows ◽  
Wall Effect ◽  
Immersed Boundary ◽  
Rigid Sphere ◽  
Rigid Spheres

The presence of a wall near a rigid sphere is known to disturb the particle fore and aft flow field and thereby affect particle drag and lift. This effect has wide ranging implications in particulate flows such as the dynamics of blood cells in microvessels or the transport of particulates in channel and pipe flows. In this study, an Immersed Boundary Direct Numerical Simulation (IB-DNS) is used to predict the dynamics of a rigid spherical body in the presence of a wall at laminar flows. The wall effect is shown to be significant when the dimensionless ratio (L/D) of the particle diameter (D) to the wall distance (L) is less than 3, and when particle Reynolds number is less than 10. Based on the IB-DNS results, a correlation for the wall effect on drag coefficient is derived that can be used to predict the actual drag coefficient for rigid spheres under the influence of a wall for L/D between 0.75 and 3 and Reynolds number between 0.18 and 10. The data underlying the correlation developed herein is validated by comparison to published experimental, numerical, and analytical correlations. The application of the IB-DNS method to study the wall effect is both novel and significant. It is novel in that such an application is not yet demonstrated. It is significant in that it; (1) utilizes a uniform Cartesian fluid mesh and (2) requires no sub domains of higher grid resolution in the wall gap.

An Efficient Immersed Boundary Method Based on Penalized Direct Forcing for Simulating Flows Through Real Porous Media

2012 ◽  
Author(s):  
Wim-Paul Breugem ◽  
Vincent van Dijk ◽  
René Delfos
Keyword(s):  
Porous Medium ◽  
Ct Scan ◽  
Immersed Boundary Method ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Particle Diameter ◽  
Immersed Boundary ◽  
Average Particle ◽  
Boundary Method ◽  
Direct Forcing

A computationally efficient Immersed Boundary Method (IBM) based on penalized direct forcing was employed to determine the permeability of a real porous medium. The porous medium was composed of about 9000 glass beads with an average particle diameter of 1.93 mm and a porosity of 0.367. The forcing of the IBM depends on the local solid volume fraction within a computational grid cell. The latter could be obtained from a high-resolution X-ray Computed Tomography (CT) scan of the packing. An experimental facility was built to determine the permeability of the packing experimentally. Numerical simulations were performed for the same packing based on the data from the CT scan. For a scan resolution of 0.1 mm the numerical value for the permeability was nearly 70% larger than the experimental value. An error analysis indicated that the scan resolution of 0.1 mm was too coarse for this packing.

Measurement of Effective Viscosity in Bubbly Flow Using Free-Falling Sphere

2003 ◽  
Author(s):  
Hiroshi Oiwa ◽  
Yuichi Murai ◽  
Masa-aki Ishikawa ◽  
Fujio Yamamoto
Keyword(s):  
Effective Viscosity ◽  
Two Phase Flow ◽  
Bubbly Flow ◽  
Relative Viscosity ◽  
Stress Transfer ◽  
Phase Flow ◽  
Two Phase ◽  
Falling Sphere ◽  
Phase Medium ◽  
Free Falling

Effective viscosity of bubbly two-phase flow is experimentally investigated by means of the falling sphere method. The terminal falling velocity of the sphere is measured by image processing to calculate the relative viscosity of the two-phase flow to the single-phase flow. The measurement results show that the effective viscosity is reduced for a range from 0 to 2% of void fraction as the shearing Weber number increases. This fact implies that the reduction of the effective viscosity is governed by the deformation of the bubbles, and the mechanism is explained by the interruption of the shear stress transfer in the two-phase medium.

scholarly journals Computation of Ice Shedding Trajectories Using Cartesian Grids, Penalization, and Level Sets

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Héloïse Beaugendre ◽  
François Morency ◽  
Federico Gallizio ◽  
Sophie Laurens
Keyword(s):  
Boundary Conditions ◽  
Level Sets ◽  
The Body ◽  
Cartesian Grids ◽  
Falling Sphere ◽  
Proposed Model ◽  
Efficient Alternative ◽  
Ice Shedding ◽  
Set Up ◽  
Free Falling

We propose to model ice shedding trajectories by an innovative paradigm that is based on cartesian grids, penalization and level sets. The use of cartesian grids bypasses the meshing issue, and penalization is an efficient alternative to explicitly impose boundary conditions so that the body-fitted meshes can be avoided, making multifluid/multiphysics flows easy to set up and simulate. Level sets describe the geometry in a nonparametric way so that geometrical and topological changes due to physics and in particular shed ice pieces are straight forward to follow. The model results are verified against the case of a free falling sphere. The capabilities of the proposed model are demonstrated on ice trajectories calculations for flow around iced cylinder and airfoil.

Direct numerical simulation of free falling sphere in creeping flow

2010 ◽  
Vol 24 (3-4) ◽  
pp. 109-120 ◽  
Author(s):  
Rupesh K. Reddy ◽  
Shi Jin ◽  
K. Nandakumar ◽  
Peter D. Minev ◽  
Jyeshtharaj B. Joshi
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Creeping Flow ◽  
Falling Sphere ◽  
Free Falling

Effect of Particle Diameter on the Free Falling of Particles

2002 ◽  
Vol 2002.55 (0) ◽  
pp. 165-166
Author(s):  
Hidehiro KAWANAMI ◽  
Koichiro OGATA ◽  
Katsuya FUNATSU ◽  
Yuji TOMITA
Keyword(s):  
Particle Diameter ◽  
Free Falling

Wall effects in a diamond‐anvil pressure‐cell falling‐sphere viscometer

1979 ◽  
Vol 50 (5) ◽  
pp. 3180-3184 ◽  
Author(s):  
R. G. Munro ◽  
G. J. Piermarini ◽  
S. Block
Keyword(s):  
Wall Effects ◽  
Pressure Cell ◽  
Falling Sphere ◽  
Diamond Anvil

Wall effects on a rotating sphere

2010 ◽  
Vol 657 ◽  
pp. 1-21 ◽  
Author(s):  
QIANLONG LIU ◽  
ANDREA PROSPERETTI
Keyword(s):  
Spherical Particle ◽  
Hydrodynamic Force ◽  
Infinite Plane ◽  
Wall Effects ◽  
Reference Case ◽  
Complex Behaviour ◽  
Rotating Sphere ◽  
Axis Of Rotation

The flow induced by a spherical particle spinning in the presence of no-slip planar boundaries is studied by numerical means. In addition to the reference case of an infinite fluid, the situations considered include a sphere rotating near one or two infinite plane walls parallel or perpendicular to the axis of rotation and a sphere centred within a cube. The hydrodynamic force and couple acting on the sphere exhibit a complex behaviour under the sometimes competing, sometimes cooperating action of viscous, inertial and centrifugal effects.

Direct Numerical Simulation of the Segre–Silberberg Effect Using Immersed Boundary Method

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Denis V. Esipov ◽  
Denis V. Chirkov ◽  
Dmitriy S. Kuranakov ◽  
Vasiliy N. Lapin
Keyword(s):  
Reynolds Number ◽  
Fluid Flow ◽  
Immersed Boundary Method ◽  
Particle Diameter ◽  
Practical Interest ◽  
Immersed Boundary ◽  
Rigid Particles ◽  
Boundary Method ◽  
Duct Geometry ◽  
Long Channel

Abstract One of the fundamental phenomena associated with the transport of rigid particles by the fluid flow in narrow ducts and tubes is the Segre–Silberberg effect. Experimental observations show that a spherical particle transported by the fluid flow in a long channel occupies a position of equilibrium between the wall and the centerline of the channel. In this study, this effect was numerically investigated using a novel semi-implicit immersed boundary method based on the discrete forcing approach. A uniform Cartesian mesh is used for the duct, whereas a moving Lagrangian mesh is used to track the position of the particle. Unlike previous studies, both cases of the duct geometry are considered: a round tube and a flat channel. Good agreement is shown to the available theoretical and numerical results of other studies. The problem is described by two dimensionless parameters, the channel Reynolds number, and the relative particle diameter. Parametric studies to these parameters were carried out, showing fundamental dependencies of equilibrium position on Reynolds number from 20 to 500 and on relative particle diameter from 0.2 to 0.7. It is demonstrated that the position of equilibrium becomes closer to the wall with the increase of Reynolds number, as well as with the decrease of particle diameter. In addition, the dependence of particle velocity on its diameter is investigated. The obtained results are of both theoretical and practical interest, with possible applications ranging from proppant transport to the design of microfluidic devices.

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