This work presents new semi-analytical solutions for the combined fully developed electro-osmotic pressure-driven flow in microchannels of viscoelastic fluids, described by generalised Phan-Thien–Tanner model (gPTT) recently proposed Ferrás et al. (Journal Non-Newtonian Fluid Mechanics, 269:88–99, 2019). version PTT a function trace stress tensor—the Mittag–Leffler function—where one or two fit...

this paper presents a numerical simulation of developing flow and heat transfer of a viscoelastic fluid in a rectangular duct. in fully developed flow of a viscoelastic fluid in a non-circular duct, secondary flows normal to the flow direction are expected to enhance the rate of heat and mass transfer. on the other hand, properties such as viscosity, thermal conductivity, specific heat and rela...

In the discipline of non-Newtonian materials, the ability to control viscoelastic stresses is very desirable in ascertaining important properties of the influenced materials. We apply the nonlinear geometric control theory to examine the controllability of various popular constitutive models with imposed homogeneous extensional flow. The subsequent constitutive laws considered here include the ...

We investigate finite amplitude stability of spatially inhomogeneous steady state an incompressible viscoelastic fluid which occupies a mechanically isolated vessel with walls kept at non-uniform temperature. For wide class models including the Oldroyd-B model, Giesekus FENE-P Johnson–Segalman and Phan–Thien–Tanner model we prove that is stable subject to any perturbation.

For many commonly used viscoelastic constitutive equations, it is well known that the limiting behavior of Oldroyd-B model. Here, we compare response simplified linear form Phan-Thien–Tanner model (“sPTT”) [Phan-Thien and Tanner, “A new equation derived from network theory,” J. Non-Newtonian Fluid Mech. 2, 353–365 (1977)] finitely extensible nonlinear elastic (“FENE”) dumbbell follows Peterlin ...

In this general lecture, we shall rst outline the way computational non-Newtonian uid mechanics di ers from conventional CFD. We do this by brie y outlining the major historical developments in this relatively new eld of science, which is conveniently called Computational Rheology. To illustrate essential features, we limit the discussion to the Oldroyd B, UCM and Phan-Thien/Tanner constitutive...

A thin filament model is used to analyze the stability of a viscoelastic thread subject to uniaxial stretching. Linear stability analysis is carried out for a number of different constitutive models, namely the Johnson–Segalman, Giesekus, Phan–Thien Tanner, and FENE–CR. Our analysis shows that stability is controlled by the competing effects of surface tension which is destabilizing and axial n...