Effect of Peripheral Layer on Peristaltic Transport of a Micropolar Fluid

Peristaltic transport of two fluid model with micropolar fluid in the core region and Newtonian fluid in the peripheral layer is studied under the assumptions of long wavelength and low Reynolds number. The linearised equations governing the flow are solved and closed form expressions for pressure rise, time averaged flux and frictional force have been obtained. The effects of various parameters on these flow variables have been studied. It is found that the pressure rise increases with micropolar parameter (m) and central mean radius (η), but decreases with coupling number (N) and viscosity ratio (µ¯). The frictional force (F¯) decreases with coupling number (N) and viscosity ratio (µ¯) but increases with micropolar parameter (m) and mean radius of central layer (η)

Motion of a Self-Propelling Micro-Organism in a Channel Under Peristalsis: Effects of Viscosity Variation

The motion of a self propelling micro-organism symmetrically located in a rectangular channel containing viscous fluid has been studied by considering the peristaltic and longitudinal waves travelling along the walls of the channel. Theexpressions for the velocity of the micro-organism and time average flux have been obtained under long wavelength approximation by taking into account the viscosity variation of the fluid across the channel. Particular cases for constant viscosity and when it is represented by a step function have been discussed. It has been observed that the velocity of the micro-organism decreases as the viscosity of the peripheral layer increases and its thickness decreases

Effect of Slip Condition on Coup le Stress Fluid Flow in a Channel with Mild Stenosis in the Presence of Uniform Magnetic Field

The s teady flow of an incompressible couple stress fluid in a two dimensional uniform channel with stenosis under the influence of a magnetic field has been investigated. Assuming the stenosis to be mild, the flow equations have been analy tically solved using the slip condition and expressions for the resistance to flow and wall shear stress have been derived. The effects of various parameters on these flow variables have been studied. It is found that the resistance to flow as well as the wall shear stress increase with the height of the stenosis and decrease with the couple stress and magnetic parameters. The effects of other parameters on resistance to flow and the wall shear stress have been considered

EFFECTS OF SLIP CONDITION AND MULTIPLE CONSTRICTIONS ON COUPLE STRESS FLUID FLOW THROUGH A CHANNEL OF NON UNIFORM CROSS SECTION

ABSTRACT Steady incompressible couple stress fluid flow through a non-uniform channel with two stenoses is investigated. Assuming the stenoses to be mild and using the slip boundary condition, the equations governing the flow of the proposed model are solved and closed form expressions for the flow characteristics (resistance to flow and wall shear stress) are derived. Both the resistance to flow and the wall shear stress increase with the heights of the stenoses and slip parameter but decrease with Darcy number. The effects of wall exponent parameter on the flow characteristics also have been studied

Effect of Homogeneous and Heterogeneous Chemical Reactions on Peristaltic Transport of a Jeffrey Fluid through a Porous Medium with Slip Condition

In this paper, the dispersion of solute matter in a Jeffrey fluid flow through a porous medium in a peristaltic channel has been investigated under the influence of slip boundary conditions. Long wavelength approximation and Taylor's limiting condition are used to obtain the average effective dispersion coefficient in both the cases of homogeneous and heterogeneous chemical reactions. The effects of various pertinent parameters on the effective dispersion coefficient are discussed. Average effective dispersion coefficient increases with amplitude ratio. That is, more dispersion in the presence of peristalsis. Further, the average effective dispersion coefficient increases with the permeability parameter and the slip parameter; but decreases with the Jeffrey number, homogeneous / heterogeneous chemical reaction rate parameter

Peristaltic flow and hydrodynamic dispersion of a reactive micropolar fluid-simulation of chemical effects in the digestive process

The hydrodynamic dispersion of a solute in peristaltic flow of a reactive incompressible micropolar biofluid is studied as a model of chyme transport in the human intestinal system with wall effects. The long wavelength approximation, Taylor's limiting condition and dynamic boundary conditions at the flexible walls are used to obtain the average effective dispersion coefficient in the presence of combined homogeneous and heterogeneous chemical reactions. The effects of various pertinent parameters on the effective dispersion coefficient are discussed. It is observed that average effective dispersion coefficient increases with amplitude ratio which implies that dispersion is enhanced in the presence of peristalsis. Furthermore average effective dispersion coefficient is also elevated with the micropolar rheological and wall parameters. Conversely dispersion is found to decrease with cross viscosity coefficient, homogeneous and heterogeneous chemical reaction rates. The present simulations provide an important benchmark for future chemo-fluid-structure interaction computational models

Magnetic micro-swimmers propelling through bio-rheological liquid bounded within an active channel

The dynamics of a micro-organism swimming through a channel with undulating walls subject to constant transverse applied magnetic field is investigated. The micro-organism is modeled as self-propelling undulating sheet which is out of phase with the channel waves while the electrically conducting biofluid (through which micro-swimmers propel) is characterized by the non-Newtonian shear-rate dependent Carreau fluid model. Creeping flow is mobilized in the channel due to the self-propulsion of the micro-organism and the undulatory motion of narrow gapped walls. Under these conditions the conservation equations are formulated under the long wavelength and low Reynolds number assumptions. The speed of the self-propelling sheet and the rate of work done at higher values of rheological parameters are obtained by using a hybrid numerical technique (MATLAB routine bvp-4c combined with a modified Newton-Raphson method). The results are validated through an alternative hybrid numerical scheme (implicit finite difference method (FDM) in conjunction with a modified Newton-Raphson method). The assisting role of magnetic field and rheological effects of the surrounding biofluid on the swimming mode are shown graphically and interpreted at length. The global behavior of biofluid is also expounded via visualization of the streamlines in both regions (above and below the swimming sheet) for realistic micro-organism speeds. The computations reveal that optimal swimming conditions for the micro-organism (i.e., greater speed with lower energy losses) are achievable in magnetohydrodynamic (MHD) environments including magnetic field-assisted cervical treatments. Keywords: Micro-organism; peristaltic (active) channel; Carreau fluid; Swimming speed; biomagnetohydrodynamics (bioMHD); Rate of work done; Hybrid numerical method, Newton-Raphson method; Cervical magnetic therap