Inclusion of lubrication forces in dynamic simulations

Sangani, Ashok S.; Mo, Guobiao

doi:10.1063/1.868228

Cited by 86 publications

(64 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Most of the methods which have been developed to circumvent this difficulty are based on asymptotics [2,4,13,14,20,23,24,31] that correctly describe the closeto-touching interaction for special geometries. However, there has been no efficient method that allows for accurate evaluation of the field in arbitrary dispersions.…”

Section: Introductionmentioning

confidence: 99%

A Method of Images for the Evaluation of Electrostatic Fields in Systems of Closely Spaced Conducting Cylinders

Cheng¹,

Greengard²

1998

SIAM J. Appl. Math.

View full text Add to dashboard Cite

Abstract.A long-standing area of materials science research has been the study of electrostatic, magnetic, and elastic fields in composites with densely packed inclusions whose material properties differ markedly from that of the background. While powerful tools exist for dilute suspensions, accurate calculations in the close-to-touching case have been carried out largely by asymptotic methods and only for simple geometries such as regular arrays of cylinders or spheres. In this paper, we develop a hybrid numerical method for the evaluation of electrostatic fields in composites consisting of arbitrary dispersions of cylinders. Our approach is based on an integral equation formulation of the governing interface problem combined with a new method of images. High accuracy is achieved using only a small number of degrees of freedom for each inclusion.

show abstract

Section: Introductionmentioning

confidence: 99%

A Method of Images for the Evaluation of Electrostatic Fields in Systems of Closely Spaced Conducting Cylinders

Cheng¹,

Greengard²

1998

SIAM J. Appl. Math.

View full text Add to dashboard Cite

show abstract

“…For h Ͻ 1.5a, it may be necessary to add lubrication forces explicitly and the force dipoles to account for the velocity they induce as was done by Sangani and Mo. 35 Since the force dipoles due to lubrication effects by Sangani and Mo 35 were expressed in terms of Lamb's multipoles, the image system derived here could be readily used to incorporate the lubrication effects while keeping N s small. Accurate estimates of f v w for the indicated values of h / a in Table II were previously determined by Brenner 22 and for f h w and t h w by Chaoui and Feuillebois.…”

Section: ͑36͒mentioning

confidence: 99%

A method for determining Stokes flow around particles near a wall or in a thin film bounded by a wall and a gas-liquid interface

Ozarkar

Sangani

2008

Physics of Fluids

Self Cite

View full text Add to dashboard Cite

A method for determining Stokes flow around particles near a wall or in a thin film bounded by a wall on one side and a nondeformable gas-liquid interface on the other side is developed. The no-slip boundary conditions at the wall are satisfied by constructing an image system based on Lamb's multipoles. Earlier results for the image systems for the flow due to a point force or a force dipole are extended to image systems for force or source multipoles of arbitrary orders. For the case of a film, the image system consists of an infinite series of multipoles on both sides of the film. Accurate evaluation of the flow due to these images is discussed, including the use of Shanks transforms. The method is applied to several problems including chains of particles, radially expanding particles, drops, and porous particles.

show abstract

“…19 More recently, solutions for flow in two-dimensional random arrays of cylinders were provided. Sangani and Yao 20 used the periodic singular solution of the Laplace equation to calculate the stream function and vorticity fields, while Sangani and Mo 21 employed a multipole expansion method to incorporate lubrication forces among particles and were able to deal with a larger number of fibers than in Ref. 20.…”

Section: F Umentioning

confidence: 99%

Permeability calculations in three-dimensional isotropic and oriented fiber networks

et al. 2008

View full text Add to dashboard Cite

Hydraulic permeabilities of fiber networks are of interest for many applications and have been studied extensively. There is little work, however, on permeability calculations in three-dimensional random networks. Computational power is now sufficient to calculate permeabilities directly by constructing artificial fiber networks and simulating flow through them. Even with today's high-performance computers, however, such an approach would be infeasible for large simulations. It is therefore necessary to develop a correlation based on fiber volume fraction, radius, and orientation, preferably by incorporating previous studies on isotropic or structured networks. In this work, the direct calculations were performed, using the finite element method, on networks with varying degrees of orientation, and combinations of results for flows parallel and perpendicular to a single fiber or an array thereof, using a volume-averaging theory, were compared to the detailed analysis. The detailed model agreed well with existing analytical solutions for square arrays of fibers up to fiber volume fractions of 46% for parallel flow and 33% for transverse flow. Permeability calculations were then performed for isotropic and oriented fiber networks within the fiber volume fraction range of 0.3%-15%. When drag coefficients for spatially periodic arrays were used, the results of the volume-averaging method agreed well with the direct finite element calculations. On the contrary, the use of drag coefficients for isolated fibers overpredicted the permeability for the volume fraction range that was employed. We concluded that a weighted combination of drag coefficients for spatially periodic arrays of fibers could be used as a good approximation for fiber networks, which further implies that the effect of the fiber volume fraction and orientation on the permeability of fiber networks are more important than the effect of local network structure.

show abstract

Inclusion of lubrication forces in dynamic simulations

Cited by 86 publications

References 11 publications

A Method of Images for the Evaluation of Electrostatic Fields in Systems of Closely Spaced Conducting Cylinders

A Method of Images for the Evaluation of Electrostatic Fields in Systems of Closely Spaced Conducting Cylinders

A method for determining Stokes flow around particles near a wall or in a thin film bounded by a wall and a gas-liquid interface

Permeability calculations in three-dimensional isotropic and oriented fiber networks

Contact Info

Product

Resources

About