Journal ArticleDOI
Dimensionless non-Newtonian fluid mechanics
TLDR
In this article, the authors present an alternative reasoning for the choice of characteristic quantities to be employed in the non-dimensionalization of the governing equations of non-Newtonian fluid flow problems.Abstract:
I present an alternative reasoning for the choice of characteristic quantities to be employed in the non-dimensionalization of the governing equations of non-Newtonian fluid flow problems The usual non-dimensionalization procedure generates well known dimensionless groups such as the Reynolds number, Deborah or Weissenberg number, Carreau number, Bingham number, and capillary number The groups that represent dimensionless rheological properties (eg Deborah number, Carreau number and Bingham number) involve flow quantities such as characteristic velocities or deformation rates Consequently, for a fixed flowing material, the values of these groups change with the flow rate In the alternative procedure, the resulting dimensionless rheological groups are actually dimensionless rheological properties, and thus remain fixed for a given flowing material Moreover, each set of values of these dimensionless rheological properties defines a class of rheologically equivalent materials The proposed non-dimensionalization procedure is physically more sound, and renders simpler both the application of dimensionless results to engineering situations and the comparisons between numerical and experimental results in scientific investigationsread more
Citations
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Modeling the thixotropic behavior of structured fluids
TL;DR: In this article, a novel approach for modeling the mechanical behavior of thixotropic viscoplastic fluids is presented, which involves two evolution equations, one for the stress and the other for the structure parameter.
Journal ArticleDOI
Thixotropic elasto-viscoplastic model for structured fluids
TL;DR: In this paper, a constitutive model for structured fluids is presented, which is composed of two differential equations, one for the stress and the other for the structure parameter, a scalar quantity that represents the structuring level of the fluid.
Journal ArticleDOI
A unified approach to model elasto-viscoplastic thixotropic yield-stress materials and apparent yield-stress fluids
TL;DR: In this article, a constitutive model for elasto-viscoplastic thixotropic materials is proposed, consisting of two differential equations, one for the stress and the other for the structure parameter, a scalar quantity that indicates the structuring level of the microstructure.
Journal ArticleDOI
Entropy analysis for magnetohydrodynamic flow and heat transfer of a Jeffrey nanofluid over a stretching sheet
TL;DR: In this paper, the entropy generation for steady laminar two-dimensional forced convection magnetohydrodynamic (MHD) boundary layer flow, heat transfer and mass transfer of an incompressible non-Newtonian nanofluid over a linearly stretching, impermeable and isothermal sheet with viscous dissipation is numerically studied.
Journal ArticleDOI
Viscoplastic dimensionless numbers
TL;DR: In this article, the authors analyze the dimensionless numbers that concern the flow of viscoplastic materials and show that the characteristic stress should be defined as the extra-stress intensity evaluated at a characteristic (maximum) deformation rate.
References
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Journal ArticleDOI
An Experimental Investigation of the Circumstances Which Determine Whether the Motion of Water Shall Be Direct or Sinuous, and of the Law of Resistance in Parallel Channels
TL;DR: In this article, it was shown that the general character of the motion of fluids in contact with solid surfaces depends on the relation between a physical constant of the fluid and the product of the linear dimensions of the space occupied by the fluid.
Journal ArticleDOI
The shear-induced solid–liquid transition in yield stress materials with chemically different structures
Peter Heinz Theodore Uhlherr,J. Guo,Carlos Tiu,X.-M. Zhang,J.Z.-Q. Zhou,T.-N. Fang,T.-N. Fang +6 more
TL;DR: In this article, a transition stress plateau separates the regions of solid behaviour and liquid behaviour, and the slope of the plateau reflects the uniformity of the structure, and hence the distribution of bonding strength within this structure.
Journal ArticleDOI
Application of the augmented Lagrangian method to steady pipe flows of Bingham, Casson and Herschel-Bulkley fluids
Raja R. Huilgol,Zhenjiang You +1 more
TL;DR: In this article, the augmented Lagrangian method is applied to the steady flow problems of Bingham, Casson and Herschel-Bulkley fluids in pipes of circular and square cross-sections.
Journal ArticleDOI
Viscosity Function for Yield-Stress Liquids
TL;DR: In this paper, a viscosity function for highly-shear-thinning or yield-stress liquids such as pastes and slurries is proposed and fitted to data for Carbopol aqueous solutions at two different concentrations, a drilling fluid, an oil emulsion, a commercial mayonnaise, and a paper coating formulation.
Journal ArticleDOI
Flow of viscoplastic liquids through axisymmetric expansions-contractions
TL;DR: In this article, the internal flow of viscoplastic liquids through ducts consisting of an abrupt axisymmetric expansion followed by an abrupt contraction was examined, and steady, inertialess numerical solutions were obtained by solving the conservation equations of mass and momentum via the finite volume method.