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Now showing items 11-20 of 24
Converged solutions of the Newtonian extrudate-swell problem
(1999)
Both the axisymmetric and the planar Newtonian extrudate-swell problems are solved using the standard and the singular finite element methods. In the latter method, special elements that incorporate the radial form of the ...
Comparison of two methods for the computation of singular solutions in elliptic problems
(1997)
We compare two numerical methods for the solution of elliptic problems with boundary singularities. The first is the integrated singular basis function method (ISBFM), a finite-element method in which the solution is ...
Flow development in compression of a finite amount of a Bingham plastic
(2007)
The flow and shape evolution during the compression of a finite amount of a Bingham plastic is investigated by means of numerical simulations. The problem relates to the popular compression test used for the rheological ...
The time-independent, compressible Poiseuille and extrudate-swell flows of a Carreau fluid with slip at the wall
(2003)
We solve the time-dependent, compressible Poiseuille and extrudate-swell flows of a shear-thinning fluid that obeys the Carreau constitutive model, using finite elements in space and a fully-implicit scheme in time. Slip ...
Mechanism for extrusion instabilities in polymer melts
(1999)
A mechanism for explaining some of the instabilities observed during the extrusion of polymer melts is further explored. This is based on the combination of non-monotonic slip and elasticity, which permits the existence ...
Squeeze flow of thixotropic semisolid slurries
(2014)
An essential element for the integration of a semisolid process in the production of complex commercial components is the availability of accurate mathematical and computational tools that could describe both the rheological ...
Viscoplastic flow development in tubes and channels with wall slip
(2016)
The development of Bingham plastic flow in tubes and channels is investigated numerically using the Papanastasiou regularization and finite element simulations. It is assumed that slip occurs along the wall following ...
Viscoplastic flow development in a channel with slip along one wall
(2017)
The flow development of a Herschel–Bulkley fluid in a horizontal channel is considered assuming that slip occurs only on the upper wall due to slip heterogeneities. Hence, the velocity profile is allowed to be asymmetric ...
Development of confined viscoplastic flows with heterogeneous wall slip
(National Technical University of Athens, 2016)
The steady, pressure-driven flow of a Herschel-Bulkley fluid in a channel is considered assuming that slip occurs on one wall only due to slip heterogeneities. Hence, the velocity profile is allowed to be asymmetric. The ...
Thixotropic flow past a cylinder
(2014)
We study the flow of a thixotropic fluid around a cylinder. The rheology of the fluid is described by means of a structural viscoplastic model based on the Bingham constitutive equation, regularised using the Papanastasiou ...