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Flow instabilities of Herschel-Bulkley fluids
(2003)
We investigate numerically the interactions of two-dimensional jets of Bingham plastic and Herschel-Bulkley fluids with a vertical surface at a distance from the die exit. This problem simulates the early stages of filling ...
On numerical simulations of polymer extrusion instabilities
(2002)
The objective of this study is mainly to review recent work concerning the numerical modeling of the stick-slip and gross melt fracture polymer extrusion instabilities. Three different mechanisms of instability are discussed: ...
Squeeze flow of semi-solid slurriesAAA
(2013)
A standard method used to determine material properties of semi-solid slurries is the squeeze flow experiment in which a fixed amount of material is squeezed under constant force or velocity. The relation between the force ...
Determining true material constants of semisolid slurries from rotational rheometer data
(2016)
In this work we revisit the issue of obtaining true material constants for semisolid slurries. Therefore, we consider the circular Couette flow of Herschel-Bulkley fluids. We first show how true constants can be obtained ...
Stability of the annular Poiseuille flow of a Newtonian liquid with slip along the walls
(2008)
The annular Poiseuille flow of a compressible Newtonian fluid is studied assuming that slip occurs along the wall. Different slip models relating the wall shear stress to the slip velocity are employed. In the case of ...
Cessation of annular Poiseuille flows of Bingham plastics
(2007)
We numerically solve the cessation of the annular Poiseuille flow of Bingham plastics for various values of the diameter ratio, using the regularized constitutive equation proposed by Papanastasiou and employing finite ...
Wall shear rates in circular couette flow of a Herschel-Bulkley fluid
(2009)
The objective of this work is to study quantitatively the errors introduced by the standard Newtonian and power-law assumptions used in the determination of the material properties of viscoplastic fluids from circular ...
Cessation of Couette and Poiseuille flows of a Bingham plastic and finite stopping times
(2005)
We solve the one-dimensional cessation Couette and Poiseuille flows of a Bingham plastic using the regularized constitutive equation proposed by Papanastasiou and employing finite elements in space and a fully implicit ...
Stability of the annular Poiseuille flow of a Newtonian liquid with slip along the walls
(2009)
The annular Poiseuille flow a Newtonian fluid is studied assuming that slip occurs along the walls. Different slip models relating the wall shear stress to the slip velocity are employed. In the case of non-monotonic slip ...
Analysis of the singular function boundary integral method for a biharmonic problem with one boundary singularity
(2012)
In this article, we analyze the singular function boundary integral method (SFBIM) for a two-dimensional biharmonic problem with one boundary singularity, as a model for the Newtonian stick-slip flow problem. In the SFBIM, ...