Generalized couette flow of a non-Newtonian fluid in annuli. Reply to comments

1982 ◽  
Vol 21 (1) ◽  
pp. 98-99 ◽  
Author(s):  
Sheng H. Lin ◽  
Chung C. Hsu
Keyword(s):  
2010 ◽  
Vol 65 (6) ◽  
pp. 2258-2262 ◽  
Author(s):  
Guangzheng Zhou ◽  
Wei Ge ◽  
Jinghai Li
Keyword(s):  

1980 ◽  
Vol 19 (4) ◽  
pp. 421-424 ◽  
Author(s):  
Sheng H. Lin ◽  
Chung C. Hsu
Keyword(s):  

2018 ◽  
Vol 21 (4) ◽  
pp. 1073-1103 ◽  
Author(s):  
Libo Feng ◽  
Fawang Liu ◽  
Ian Turner ◽  
Liancun Zheng

Abstract In this paper, we consider the application of the finite difference method for a class of novel multi-term time fractional viscoelastic non-Newtonian fluid models. An important contribution of the work is that the new model not only has a multi-term time derivative, of which the fractional order indices range from 0 to 2, but also possesses a special time fractional operator on the spatial derivative that is challenging to approximate. There appears to be no literature reported on the numerical solution of this type of equation. We derive two new different finite difference schemes to approximate the model. Then we establish the stability and convergence analysis of these schemes based on the discrete H1 norm and prove that their accuracy is of O(τ + h2) and O(τmin{3–γs,2–αq,2–β}+h2), respectively. Finally, we verify our methods using two numerical examples and apply the schemes to simulate an unsteady magnetohydrodynamic (MHD) Couette flow of a generalized Oldroyd-B fluid model. Our methods are effective and can be extended to solve other non-Newtonian fluid models such as the generalized Maxwell fluid model, the generalized second grade fluid model and the generalized Burgers fluid model.


1997 ◽  
Vol 343 ◽  
pp. 73-94 ◽  
Author(s):  
P. Y. HUANG ◽  
J. FENG ◽  
H. H. HU ◽  
D. D. JOSEPH

This paper reports the results of direct numerical simulation of the motion of a two-dimensional circular cylinder in Couette flow and in Poiseuille flow of an Oldroyd-B fluid. Both neutrally buoyant and non-neutrally buoyant cylinders are considered. The cylinder's motion and the mechanisms which cause the cylinders to migrate are studied. The stable equilibrium position of neutrally buoyant particles varies with inertia, elasticity, shear thinning and the blockage ratio of the channel in both shear flows. Shear thinning promotes the migration of the cylinder to the wall while inertia causes the cylinder to migrate away from the wall. The cylinder moves closer to the wall in a narrower channel. In a Poiseuille flow, the effect of elastic normal stresses is manifested by an attraction toward the nearby wall if the blockage is strong. If the blockage is weak, the normal stresses act through the curvature of the inflow velocity profile and generate a lateral force that points to the centreline. In both cases, the migration of particles is controlled by elastic normal stresses which in the limit of slow flow in two dimensions are compressive and proportional to the square of the shear rate on the body. A slightly buoyant cylinder in Couette flow migrates to an equilibrium position nearer the centreline of the channel in a viscoelastic fluid than in a Newtonian fluid. On the other hand, the same slightly buoyant cylinder in Poiseuille flow moves to a stable position farther away from the centreline of the channel in a viscoelastic fluid than in a Newtonian fluid. Marked effects of shear thinning are documented and discussed.


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