The lift on a small sphere in wall-bounded linear shear flows

1993 ◽  
Vol 246 ◽  
pp. 249-265 ◽  
Author(s):  
John B. McLaughlin
Keyword(s):  
Shear Flow ◽  
Closed Form ◽  
Lift Force ◽  
Closed Form Solution ◽  
Analytical Form ◽  
Form Solution ◽  
Rigid Sphere ◽  
Small Sphere ◽  
Bounded Linear ◽  
Linear Shear

This paper presents a closed-form solution for the inertial lift force acting on a small rigid sphere that translates parallel to a flat wall in a linear shear flow. The results provide connections between results derived by other workers for various limiting cases. An analytical form for the lift force is derived in the limit of large separations. Some new results are presented for the disturbance flow created by a small rigid sphere translating through an unbounded linear shear flow.

Shear versus vortex-induced lift force on a rigid sphere at moderate Re

2002 ◽  
Vol 473 ◽  
pp. 379-388 ◽  
Author(s):  
P. BAGCHI ◽  
S. BALACHANDAR
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Shear Flow ◽  
Lift Force ◽  
Lift Coefficient ◽  
Rigid Sphere ◽  
Free Rotation ◽  
Rigid Spheres ◽  
Linear Shear ◽  
Strong Lift

The lift forces on rigid spheres entrained in a vortex and a linear shear flow are computed using a direct numerical simulation. The sphere Reynolds number is in the range 10 to 100. The lift coefficient in a vortex is shown to be nearly two orders of magnitude higher than that in a shear flow. The inviscid mechanism is shown to be inadequate to account for the enhanced lift force. The effect of free rotation of the sphere is also shown to be too small to account for the enhanced lift force. Flow structure around the sphere is studied to explain the generation of the strong lift force in a vortex.

scholarly journals A JKR-Like Solution for Viscoelastic Adhesive Contacts

2021 ◽  
Vol 7 ◽  
Author(s):  
Guido Violano ◽  
Antoine Chateauminois ◽  
Luciano Afferrante
Keyword(s):  
Closed Form ◽  
Numerical Models ◽  
Closed Form Solution ◽  
Numerical Data ◽  
Adhesive Contact ◽  
Form Solution ◽  
Contact Radius ◽  
Rigid Sphere ◽  
Soft Spheres ◽  
Adhesive Contacts

A closed-form solution for the adhesive contact of soft spheres of linear elastic material is available since 1971 thanks to the work of Johnson, Kendall, and Roberts (JKR). A similar solution for viscoelastic spheres is still missing, though semi-analytical and numerical models are available today. In this note, we propose a closed-form analytical solution, based on JKR theory, for the detachment of a rigid sphere from a viscoelastic substrate. The solution returns the applied load and contact penetration as functions of the contact radius and correctly captures the velocity-dependent nature of the viscoelastic pull-off. Moreover, a simple approach is provided to estimate the stick time, i.e., the delay between the time the sphere starts raising from the substrate and the time the contact radius starts reducing. A simple formula is also suggested for the viscoelastic pull-off force. Finally, a comparison with experimental and numerical data is shown.

scholarly journals Drag and lift forces on a rigid sphere immersed in a wall-bounded linear shear flow

2021 ◽  
Vol 6 (10) ◽  
Author(s):  
Pengyu Shi ◽  
Roland Rzehak ◽  
Dirk Lucas ◽  
Jacques Magnaudet
Keyword(s):  
Shear Flow ◽  
Rigid Sphere ◽  
Bounded Linear ◽  
Linear Shear ◽  
Lift Forces ◽  
Drag And Lift

The inertial lift on a rigid sphere in a linear shear flow field near a flat wall

1994 ◽  
Vol 263 ◽  
pp. 1-18 ◽  
Author(s):  
Pradeep Cherukat ◽  
John B. Mclaughlin
Keyword(s):  
Shear Flow ◽  
Flow Field ◽  
Lift Force ◽  
Point Force ◽  
Rigid Sphere ◽  
Flat Wall ◽  
Linear Shear ◽  
Inner Region ◽  
Infinite Wall

An expression which predicts the inertial lift, to lowest order, on a rigid sphere translating in a linear shear flow field near a flat infinite wall has been derived. This expression may be used when the wall lies within the inner region of the sphere's disturbance flow. It is valid even when the gap is small compared to the radius of the sphere. When the sphere is far from the wall, the lift force predicted by the present analysis converges to the value predicted by earlier analyses which consider the sphere as a point force or a force doublet singularity. The effect of rotation of the sphere on the lift has also been analysed.

scholarly journals Analytical Closed-Form Solution for General Factor with Many Variables

2020 ◽  
Vol 18 (1) ◽  
pp. 2-23
Author(s):  
Stan Lipovetsky ◽  
Vladimir Manewitsch
Keyword(s):  
Closed Form ◽  
Latent Variable ◽  
Closed Form Solution ◽  
Analytical Form ◽  
Theoretical Description ◽  
Form Solution ◽  
General Factor ◽  
Practical Application ◽  
Factor Solution ◽  
Latent Factor

The factor analytic triad method of one-factor solution gives the explicit analytical form for a common latent factor built by three variables. The current work considers analytical presentation of a general latent factor constructed in a closed-form solution for multivariate case. The results can be supportive to theoretical description and practical application of latent variable modeling, especially for big data because the analytical closed-form solution is not prone to data dimensionality.

On a Closed-Form Solution of Prandtl's System of Equations

2013 ◽  
Vol 40 (2) ◽  
pp. 106-114
Author(s):  
J. Venetis ◽  
Aimilios (Preferred name Emilios) Sideridis
Keyword(s):  
Closed Form ◽  
Closed Form Solution ◽  
Form Solution ◽  
System Of Equations
Sign in / Sign up

Export Citation Format

Share Document