Effect on flow characteristics of blood in overlapping stenosed artery considering the axial variation of viscosity using power-law non-Newtonian fluid model

2020 ◽  
Vol 11 (4) ◽  
pp. 397
Author(s):  
Kanika Gujral ◽  
S.P. Singh
Keyword(s):  
Newtonian Fluid ◽  
Power Law ◽  
Fluid Model ◽  
Flow Characteristics ◽  
Stenosed Artery ◽  
Axial Variation

A Non-Newtonian Fluid Flow Model for the Slip Condition on Blood Flow through a Stenosed Artery using Power-law Fluid

2018 ◽  
Vol 9 (7) ◽  
pp. 871-879
Author(s):  
Rajesh Shrivastava ◽  
R. S. Chandel ◽  
Ajay Kumar ◽  
Keerty Shrivastava and Sanjeet Kumar
Keyword(s):  
Blood Flow ◽  
Fluid Flow ◽  
Newtonian Fluid ◽  
Power Law ◽  
Flow Model ◽  
Slip Condition ◽  
Power Law Fluid ◽  
Stenosed Artery ◽  
Flow Through

MICROPOLAR FLUID MODEL FOR BLOOD FLOW THROUGH A STENOSED ARTERY

2013 ◽  
Vol 05 (04) ◽  
pp. 1350043 ◽  
Author(s):  
H. ASADI ◽  
K. JAVAHERDEH ◽  
S. RAMEZANI
Keyword(s):  
Blood Flow ◽  
Fluid Flow ◽  
Excellent Agreement ◽  
Micropolar Fluid ◽  
Degrees Of Freedom ◽  
Fluid Model ◽  
Flow Characteristics ◽  
Element Formulation ◽  
Stenosed Artery ◽  
Circular Microchannel

Various experimental observations have demonstrated that the classical fluid theory is incapable of explaining many phenomena at micro and nano scales. On the other hand, micropolar fluid dynamics can naturally pick up the physical phenomena at these scales owing to its additional degrees of freedom caused by incorporating the effects of fluid molecules on the continuum. Therefore, one of the aims of this paper is to investigate the applicability of the theory of micropolar fluids to modeling and calculating flows in circular microchannels depending on the geometrical dimension of the flow field. Hence, a finite element formulation for the numerical analysis of micropolar laminar fluid flow is developed. In order to validate the results of the FE formulation, the analytical and exact solution of the micropolar Hagen–Poiseuille flow in a circular microchannel is presented, and an excellent agreement between the results of the analytical solution and those of the FE formulation is observed. It is also shown that the micropolar viscosity and the length scale parameter have significant roles on changing the flow characteristics. Then, the behavior of an incompressible viscous fluid flow such as blood flow in a stenosed artery, having multiple kinds of stenoses, is investigated. The obtained results are compared to the results reported in the literature, and an excellent agreement is observed.

Mathematical model for a Herschel-Bulkley fluid flow in an elastic tube

Open Physics ◽  
2011 ◽  
Vol 9 (5) ◽  
Author(s):  
Kuppalapalle Vajravelu ◽  
Sreedharamalle Sreenadh ◽  
Palluru Devaki ◽  
Kerehalli Prasad
Keyword(s):  
Shear Stress ◽  
Fluid Flow ◽  
Wall Shear Stress ◽  
Yield Stress ◽  
Newtonian Fluid ◽  
Power Law ◽  
Fluid Model ◽  
Elastic Tube ◽  
Yield Stress Fluid ◽  
Power Law Index

AbstractThe constitution of blood demands a yield stress fluid model, and among the available yield stress fluid models for blood flow, the Herschel-Bulkley model is preferred (because Bingham, Power-law and Newtonian models are its special cases). The Herschel-Bulkley fluid model has two parameters, namely the yield stress and the power law index. The expressions for velocity, plug flow velocity, wall shear stress, and the flux flow rate are derived. The flux is determined as a function of inlet, outlet and external pressures, yield stress, and the elastic property of the tube. Further when the power-law index n = 1 and the yield stress τ 0 → 0, our results agree well with those of Rubinow and Keller [J. Theor. Biol. 35, 299 (1972)]. Furthermore, it is observed that, the yield stress and the elastic parameters (t 1 and t 2) have strong effects on the flux of the non-Newtonian fluid flow in the elastic tube. The results obtained for the flow characteristics reveal many interesting behaviors that warrant further study on the non-Newtonian fluid flow phenomena, especially the shear-thinning phenomena. Shear thinning reduces the wall shear stress.

Onset of Convection in a Horizontal Porous Layer Saturated by a Power-Law Fluid

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Z. Alloui ◽  
N. Ben Khelifa ◽  
H. Beji ◽  
P. Vasseur
Keyword(s):  
Rayleigh Number ◽  
Newtonian Fluid ◽  
Power Law ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Finite Amplitude ◽  
Parallel Flow ◽  
Governing Equations ◽  
Onset Of Convection ◽  
Power Law Index

This paper investigates the onset of motion, and the subsequent finite-amplitude convection, in a shallow porous cavity filled with a non-Newtonian fluid. A power-law model is used to characterize the non-Newtonian fluid behavior of the saturating fluid. Constant fluxes of heat are imposed on the horizontal walls of the layer. The governing parameters of the problem under study are the Rayleigh number R, the power-law index n, and the aspect ratio of the cavity A. An analytical solution, valid for shallow enclosures (A ≫ 1), is derived on the basis of the parallel flow approximation. In the range of the governing parameters considered in this study, a good agreement is found between the analytical predictions and the numerical results obtained by solving the full governing equations. For dilatant fluids (n > 1), it is found that the onset of motion is linearly unstable, i.e., always occurs provided that the supercritical Rayleigh number RCsup≥0. For pseudoplastic fluids (n < 1), the supercritical Rayleigh number for the onset of motion is RCsup=∞. However, it is demonstrated, on the basis of the nonlinear parallel flow theory, that the onset of motion occurs above a subcritical Rayleigh number RCsub which depends upon the power-law index n. For finite-amplitude convection, the heat and flow characteristics predicted by the analytical model are found to agree well with a numerical study of the full governing equations.

scholarly journals UNSTEADY TWO-LAYERED BLOOD FLOW THROUGH A -SHAPED STENOSED ARTERY USING THE GENERALIZED OLDROYD-B FLUID MODEL

2016 ◽  
Vol 58 (1) ◽  
pp. 96-118 ◽  
Author(s):  
AKBAR ZAMAN ◽  
NASIR ALI ◽  
O. ANWAR BEG ◽  
M. SAJID
Keyword(s):  
Blood Flow ◽  
Differential Equations ◽  
Newtonian Fluid ◽  
Numerical Solutions ◽  
Fluid Model ◽  
Initial Boundary ◽  
Momentum Conservation ◽  
Rheological Parameters ◽  
Stenosed Artery ◽  
Flow Through

A theoretical study of an unsteady two-layered blood flow through a stenosed artery is presented in this article. The geometry of a rigid stenosed artery is assumed to be$w$-shaped. The flow regime is assumed to be laminar, unsteady and uni-directional. The characteristics of blood are modelled by the generalized Oldroyd-B non-Newtonian fluid model in the core region and a Newtonian fluid model in the periphery region. The governing partial differential equations are derived for each region by using mass and momentum conservation equations. In order to facilitate numerical solutions, the derived differential equations are nondimensionalized. A well-tested explicit finite-difference method (FDM) which is forward in time and central in space is employed for the solution of a nonlinear initial boundary value problem corresponding to each region. Validation of the FDM computations is achieved with a variational finite element method algorithm. The influences of the emerging geometric and rheological parameters on axial velocity, resistance impedance and wall shear stress are displayed graphically. The instantaneous patterns of streamlines are also presented to illustrate the global behaviour of the blood flow. The simulations are relevant to haemodynamics of small blood vessels and capillary transport, wherein rheological effects are dominant.

scholarly journals On Two-Fluid Blood Flow through Stenosed Artery with Permeable Wall

2014 ◽  
Vol 11 (1-2) ◽  
pp. 39-45
Author(s):  
Rupesh K. Srivastav ◽  
V. P. Srivastava
Keyword(s):  
Blood Flow ◽  
Present Model ◽  
Fluid Model ◽  
Flow Characteristics ◽  
Mechanical Study ◽  
Stenosed Artery ◽  
Flow Through ◽  
Flowing Blood ◽  
Two Fluid Model ◽  
Two Fluid

The present investigation concerns the fluid mechanical study on the effects of the permeability of the wall through an axisymmetric stenosis in an artery assuming that the flowing blood is represented by a two-fluid model. The expressions for the blood flow characteristics, the impedance, the wall shear stress distribution in the stenotic region and the shearing stress at the stenosis throat have been derived. Results for the effects of permeability as well as of the peripheral layer on these blood flow characteristics are quantified through numerical computations and presented graphically and discussed comparatively to validate the applicability of the present model.

Rheometric Studies of Functional Polyurethane Foam Composite

2017 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Jimmie C. Oxley ◽  
James L. Smith ◽  
Philipp M. Baldovi ◽  
Dennis A. Siginer
Keyword(s):  
Newtonian Fluid ◽  
Power Law ◽  
Fluid Model ◽  
Shear Thinning ◽  
Solid Content ◽  
Testing Time ◽  
Pu Foam ◽  
Foam Composite ◽  
Computer Controlled

A rheometric characterization of the functional Polyurethane (PU) foam composite with and without solid additives (aluminum flakes) were experimentally measured using a computer controlled mechanical spectrometer (rheometer) ARES-G2. It is determined that PU composite exhibits a strong time thickening and shear thinning behavior. The rheological behavior of this composite can be described with the power-law generalized non-Newtonian fluid model. The rheometric tests showed that the PU/Al mixture exhibits thermal thickening and shear thinning behavior with the yield stress. The system can be described with the power-law generalized non-Newtonian fluid (Ostwald-de-Waele) model. The effective viscosity of PU composite increases with both the testing time (exponentially) and the solid content (polynomial) in the mixture.

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