Showing papers on "Herschel–Bulkley fluid published in 1974"
TL;DR: In this article, the generalization of the Faxen theorem for the force on a sphere in an incompressible fluid to the general nonstationary case derived in a previous paper is further extended to the case of a compressible fluid.
149 citations
TL;DR: In this article, the tensile forces of a rod-shaped fluid filament were determined using a photo-graphic measurement of the filament profile and the assumption of a flat velocity profile.
74 citations
TL;DR: In this paper, an approximate solution to the flow past an impulsively started infinite plate in an elastico-viscous fluid is derived for the velocity and shearing stress.
Abstract: An approximate solution to the flow past an impulsively started infinite plate in an elastico-viscous fluid is derived for the velocity and shearing stress. It is observed that the velocity increases with increasing the elastic parameterk and the shearing stress decreases with increasingk.
62 citations
TL;DR: In this article, an experimental study of viscous heating in the flow of fluids with an exponential dependence of viscosity on temperature has shown that, for a given shear stress, two shear rates are possible.
Abstract: Theoretical investigations of viscous heating in the flow of fluids with an exponential dependence of viscosity on temperature have shown that, for a given shear stress, two shear rates are possible. Above a critical value, the stress decreases as the shear rate increases.
The present work is an experimental study of this phenomenon in plane and circular Couette flows and in cylindrical Poiseuille flow. ArochlorR 1260, a high viscosity Newtonian fluid with an extremely sensitive viscosity-temperature dependence is used as the test fluid. The results clearly show that two shear rates for Couette flow exist for one measured wall shear stress. Because of the viscosity-pressure dependence of the fluid, the Poiseuille flow results are inconclusive.
49 citations
TL;DR: In this article, the dynamics of blade-coating of a viscoelstic fluid onto a moving sheet is described by an empirical constitutive equation which shows non-Newtonian viscosity and finite normal stress behavior consistent with typical observations of polymeric fluids.
Abstract: A theory is presented which describes the dynamics of blade-coating of a viscoelstic fluid onto a moving sheet. The method begins with the usual “lubrication” approximation, and develops the solution as a perturbation about the Newtonian case. Viscoelasticity is described by an empirical constitutive equation which shows non-Newtonian viscosity and finite normal stress behavior consistent with typical observations of polymeric fluids. Theoretical results indicate a small increase in coating thickness due to departure from Newtonian behavior, and a significant decrease in the magnitude of the pressure developed under the blade. Consequently, the blade loading can be reduced significantly by viscoelastic effects. The results for the loading may be an artifact of the specific constitutive model, since it can be shown that some viscoelastic fluids, specifically an “elastic Newtonian” fluid, would exhibit increased loading relative to the inelastic Newtonian case.
36 citations
TL;DR: In this article, the problem of an elastico-viscous fluid resting on a plate which moves with a time dependent velocity in its own plane (along negative x direction) and rotating with a constant velocity Iomega; along with the fluid as a rigid body has been discussed.
Abstract: The problem of an elastico-viscous fluid resting on a plate which moves with a time dependent velocity in its own plane (along negative x direction) and rotating with a constant velocity Iomega; along with the fluid as a rigid body has been discussed, It is found that the elastic property of the fluid increases the drag and the lateral stress on the plate, The rotation introduces fluid motion in the y direction, For a fixed time and distance from the plate, the velocity fluctuates with decreasing magnitudes with increasing Iomega;, with the result that the boundary layer thickness reduces as Iomega; increases, The stresses increase parabolically with respect to Iomega;, The solution for an arbitrary velocity of the plate is also presented, In case of impulsive flows a secondary boundary layer whose thickness is of order √(vt) (v is the kinematic viscosity) is found to develop for very short times
32 citations
24 citations
2 citations