Flow and thermal convection in heat exchangers can be affected by variations in viscosity. In circular pipes the significance of this effect was expressed by Sieder and Tate’s empirical formula. Similar correction can be derived for other heat transfer problems. Exact solutions for heat transfer during the non-isoviscous laminar flow of Newtonian and non-Newtonian liquids in circular and flat d...

We present some variants of Burgers-type equations for incompressible and isothermal planar flow of viscous non-Newtonian fluids based on the Cross, the Carreau and the power-law rheology models, and on a symmetry assumption on the flow. We numerically solve the associated traveling wave equations by using industrial data and in order to validate the models we prove existence and uniqueness of ...

In this article, the electro-osmotic flow of Oldroyd-B fluid in a circular micro-channel with slip boundary condition is considered. The corresponding fractional system is represented by using a newly defined time-fractional Caputo-Fabrizio derivative without singular kernel. Closed form solutions for the velocity field are acquired by means of Laplace and finite Hankel transforms. Additionally...

It is well known that highly elastic liquids can exhibit flow characteristics which are markedly different from those found in Newtonian liquids. Nowhere is this better seen than in the case of Contraction Flows, whether axisymmetric or planar. Figure 1 shows the phenomenon of ‘vortex enhancement’, where the corner vortex (which is present in Newtonian liquids) is increased in size, often in an...

We study the Saffman-Taylor instability of a non-Newtonian fluid in a Hele-Shaw cell. Using a fluid model with shear-rate dependent viscosity, we derive a Darcy’s law whose viscosity depends upon the squared pressure gradient. This yields a natural, nonlinear boundary value problem for the pressure. A model proposed recently by Bonn et al. @Phys. Rev. Lett. 75, 2132 ~1995!# follows from this mo...

BACKGROUND Non-Newtonian fluids occur in many relevant flow and mixing scenarios at the lab and industrial scale. The addition of acid or basic solutions to a non-Newtonian fluid is not an infrequent operation, particularly in Biotechnology applications where the pH of Non-Newtonian culture broths is usually regulated using this strategy. METHODOLOGY AND FINDINGS We conducted mixing experimen...

The flow in an elastico-viscous fluid between two co-axial infinite rotating porous discs is considered for high cross flow Reynolds number. The discs are rotating with different angular velocity and the injection rate of the fluid at one disc is different from the suction rate of other disc. The effect of suction parameters on the velocity components have been investigated numerically and solv...

In the present work a two fluid model for blood flow through abnormally constrictedhuman artery (stenosed artery) has been developed. The model consists of a core region of suspensionof all erythrocytes assumed to be micro-polar fluid so as to include the micro-structural effects inaddition to the peripheral-layer viscosity effects, and a peripheral plasma layer free from cells of anykind of Ne...

A continuum theory for non-Newtonian flow of a two-phase composite containing rigid inclusions is presented. I t predicts flow suppression by a factor of (1 V)p, where V is the volume fraction of the rigid inclusion and q depends on the stress exponent and the inclusion shape. Stress concentrations in the rigid inclusion have also been evaluated. As the stress exponent increases, flow suppressi...

Flow of sour cherry (Prunus cerasus L. cv. Montmorency) gum solutions through a glass capillary was Newtonian for pressure gradients from 0 to 1.8 megapascals per meter, and hydraulic conductance was inversely proportional to solution viscosity in this range. However, flow became plastic at pressure gradients above 1.8 megapascals per meter, resulting in a decrease in solution viscosity. The ma...