scholarly journals Peristaltic Transport of a Particle–Fluid Suspension through a Uniform and Non-Uniform Annulus

2008 ◽  
Vol 5 (2) ◽  
pp. 47-57 ◽  
Author(s):  
K. S. Mekheimer ◽  
Y. Abd Elmaboud

This study looks at the influence of an endoscope on the peristaltic flow of a particle–fluid suspension (as blood model) through tubes. A long wavelength approximation through a uniform and non-uniform infinite annulus filled with an incompressible viscous and Newtonian fluid mixed with rigid spherical particles of identical size is investigated theoretically. The inner tube is uniform, rigid and moving with a constant velocity V0, whereas the outer non-uniform tube has a sinusoidal wave travelling down its wall. The axial velocity of the fluid phase uf, particulate phase upand the pressure gradients have been obtained in terms of the dimensionless flow rateQ, the amplitude ratioɸ, particle concentrationC, the velocity constant V0and the radius ratio ϵ (the ratio between the radius of the inner tube and the radius of the outer one at the inlet). Numerical calculations for various values of the physical parameters of interest are carried out for the pressure rise and the friction force on the inner and the outer tubes.

2020 ◽  
Vol 75 (8) ◽  
pp. 727-738 ◽  
Author(s):  
Ramzy M. Abumandour ◽  
Islam M. Eldesoky ◽  
Mohamed H. Kamel ◽  
Mohamed M. Ahmed ◽  
Sara I. Abdelsalam

AbstractIn the article, the effects of the thermal viscosity and magnetohydrodynamic on the peristalsis of nanofluid are analyzed. The dominant neutralization is deduced through long wavelength approximation. The analytical solution of velocity and temperature is extracted by using steady perturbation. The pressure gradient and friction forces are obtained. Numerical results are calculated and contrasted with the debated theoretical results. These results are calculated for various values of Hartmann number, variable viscosity parameter and amplitude ratio. It is observed that the pressure gradient is reduced with an increase in the thermal viscosity parameter and that the Hartmann number enhances the pressure difference.


2015 ◽  
Vol 70 (7) ◽  
pp. 513-520 ◽  
Author(s):  
Ehnber Naheed Maraj ◽  
Sohail Nadeem

AbstractThe present work is the mathematical investigation of peristaltic flow of Rabinowitsch fluid in a curved channel. The current problem is modeled and solutions for non-dimensional differential equation are obtained under low Reynolds number and long wavelength approximation. The effects of long lasting non-dimensional parameters on exact solution for velocity profile, pressure rise and shear stresses are studied graphically in the last section. Tables are also incorporated for shear stresses at the walls of the curved channel.


2015 ◽  
Vol 70 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Sohail Nadeem ◽  
Hina Sadaf

AbstractIn this article, the mechanism of cilia-induced flow is discussed through a mathematical model. In this analysis two-dimensional flow of a viscous fluid is observed in a curved channel with ciliated walls. The features of ciliary structures are determined by the dominance of viscous effects over inertial effects using the long-wavelength approximation. The flow is modeled in both fixed and wave frame references. The exact solution is calculated for the velocity profile and the flow properties for the viscous fluid are determined as a function of the cilia and metachronal wave velocity. Results for the pressure rise, pressure gradient and stream function are constructed and analyzed graphically.


2009 ◽  
Vol 02 (03) ◽  
pp. 299-309 ◽  
Author(s):  
AYMAN MAHMOUD SOBH

In this paper, we study the interaction of peristalsis with heat transfer for the flow of a viscous fluid through a porous medium in uniform and nonuniform channels. The flow is subjected to constant transverse magnetic field. Long wavelength approximation (that is, the wavelength of the peristaltic wave is large compared with the radius of the channel) is used to solve the governing system. Closed form expressions are derived for the pressure–flow relationship, temperature, and heat transfer coefficient. The effects of various physical parameters are discussed through graphs.


2016 ◽  
Vol 83 (5) ◽  
Author(s):  
Alan J. Levy ◽  
Xinyu Zhang

Tensile stability of healthy medial arterial tissue and its constituents, subject to initial geometrical and/or material imperfections, is investigated based on the long wavelength approximation. The study employs existing constitutive models for elastin, collagen, and vascular smooth muscle which comprise the medial layer of large elastic (conducting) arteries. A composite constitutive model is presented based on the concept of the musculoelastic fascicle (MEF) which is taken to be the essential building block of medial arterial tissue. Nonlinear equations governing axial stretch and areal stretch imperfection growth quantities are obtained and solved numerically. Exact, closed-form results are presented for both initial and terminal rates of imperfection growth with nominal load. The results reveal that geometrical imperfections, in the form of area nonuniformities, and material imperfections, in the form of constitutive parameter nonuniformities, either decrease or increase only slightly with increasing nominal load; a result which is to be expected for healthy tissue. By way of contrast, an examination of a simple model for elastin with a degrading stiffness gives rise to unbounded imperfection growth rates at finite values of nominal load. The latter result indicates how initial geometrical and material imperfections in diseased tissues might behave, a topic of future study by the authors.


1989 ◽  
Vol 04 (05) ◽  
pp. 1037-1053 ◽  
Author(s):  
KERSON HUANG

We give a critical review of the "triviality" of the λϕ4 theory, i.e., the vanishing of the renormalized self-coupling. Evidence from perturbation theory and Monte-Carlo simulations are cited. It is noted that (a) the theory is "trivial" but not entirely free, for there is spontaneous symmetry breaking; (b) perturbation theory is unreliable. Soluble examples with similar behavior are compared, in particular the Lee model and the 3D δ function potential. The latter case is especially important, for it shows that triviality is a symptom that the interaction is too singular, and suggests a cure. The import for the Higgs sector of the standard model is discussed. It is argued that, like the Fermi pseudopotential, the Higgs field is a long-wavelength approximation that should be used in lowest order perturbation theory only.


Sign in / Sign up

Export Citation Format

Share Document