Peristaltic pumping in non-uniform tubes

Roll of partial slip on Ellis nanofluid in the proximity of double diffusion convection and tilted magnetic field: Application of Chyme movement

The current study aims to investigate the effect of partial slip conditions over double diffusion convection. The phenomenon is applied with the inclined magnetic flux of peristaltic flow on Ellis nanofluid model in an asymmetric channel. The fundamental differential equations are constructed and solved through lubrication approximation that gives the coupled system of ordinary differential equations. This resultant system is further solved numerically, and graphic representation are used to physically comprehend the flow quantity data. The whole procedure is carried out under the trapping mechanism by drawing contour streamlines. The knowledge gained from this work will be useful in the creation of intelligent magneto-peristaltic pumps for specific heat and medication delivery phenomena.

Peristaltic activity for electro-kinetic complex driven cilia transportation through a non-uniform channel

MOTIVATIONS

Now-a-days in medical science, the transport study of biological fluids through non-uniform vessels are going to increase due to their close relation to the reality. Motivated through such type of complex transportation, the current study is presented of cilia hydro-dynamics of an aqueous electrolytic viscous fluid through a non-uniform channel under an applied axial electric field. Mathematical Formulations: Because of the complexity shape and nature of flow channel, we have used curvilinear coordinates in the derivation of continuity and momentum equationsin a fixed frame of reference. A linear transformation is used to renovate the flow system of equations from fixed (laboratory) to moving (wave) frame. For further simplification, the dimensionless variables are introduced to make the flow system of equations into the dimensionless form and at last convert these equations in term of stream function by using the mathematical terminologies of streamlines. The whole analysis is performed under (low Reynolds number) creeping phenomena and long wavelength approximation, respectively. Additionally, small ionic Peclet number and Debye-Huckel linearization are used to simplify the Nernst-Planck and Poisson-Boltzmann equations. The BVP4C technique is used to obtain the numerical solution for velocity distribution, pressure gradient, pressure rise and stream function through MATLAB.

MAIN OUTCOMES

The amplitude of velocity distribution is increased (decreased) at larger values of non-uniform parameter (cilia length). The non-uniform parameter played a vital role not only in the enhancement of circulation at the upper half of the channel but also the length of bolus increased. Results of straight channel are gained for larger value of the dimensionless radius of curvature parameter as well as cilia length.

A theoretical analysis of Biorheological fluid flowing through a complex wavy convergent channel under porosity and electro-magneto-hydrodynamics Effects

BACKGROUND AND OBJECTIVE

Flow generated via peristaltic waves in naturally occurring physical phenomenon inside human body. Its combination with electric and magnetic forces makes it even more versatile in biomedical engineering applications. The results presented in this article are useful in designing artificial tubes, lab-on-a-chip devices for cell manipulation, drug design, flow amalgamation, micro-scale pumps and micro-bots which can be externally controlled by electric and magnetic sensors. Motivated by the aforesaid facts the current investigation is based on the transportation of a couple stress bio-fluid by peristalsis through a convergent channel under the postulates of creeping phenomena and long wavelength, respectively METHODS: A closed form solution is acquired for the axial velocity profile, volumetric flow rate and streamlines, respectively. The physical influence of involved parameters on the rheological characteristics are argued analytically with the help of Mathematica software 12.0.1 in detail. Additionally, the flow system is considered to take place under the both porosity and electro-magneto-hydrodynamics effects, respectively. The amplitude of axial velocity across one wavelength is strongly affected at the larger values of numerous embedded parameters: Darcy number, Hartmann number, Electro-osmotic velocity parameter and non-Newtonian (couple stress) parameter.

RESULTS

We have observed remarkable effects of embedded parameters on velocity distribution, flow rate and trapping phenomena under porous and electro-osmotic (combination of both magnetic and electric) effects. The circulation of boluses and number of streamlines are reduced/enhanced for larger Hartmann number/Darcy number due strong magnetic/porosity effects. This research study additionally tells us how to control the transportation phenomena of biological fluids by appropriate adjusting the porosity effects (the effects of porous media) and electro-osmotic influences. Moreover, in order to enhance the performance of a peristaltic pump at the micro-scale level, we have used complex peristaltic wave scenario in the boundary walls of the convergent micro-channel.

Mechanical roles of anterograde and retrograde intestinal peristalses after feeding in a larval fish (Danio rerio)

Transport in gut is important, not only for digestion, metabolism, and nutrient uptake, but also for microbiotic circumstance in the digestive tract; however, the effects of mixing and pumping in the intestine have not been fully clarified. Therefore, in this study, we quantitatively explored intestinal mixing and pumping, represented using a dispersion coefficient and pressure rise in zebrafish larvae, which is a model organism for vertebrate digestive studies, over time by measuring transport phenomena after feeding. Here we provide the first quantitative evidence of the roles of anterograde and retrograde intestinal peristalses in the larval fish of Danio rerio after feeding in terms of digestive pumping and mixing functions by an in vivo imaging of intestinal propagation waves in the larval intestine. Peristaltic velocities in the anterior and posterior intestines change considerably after feeding for 5 h, while the intervals and amplitudes remain almost constant. The intestinal transport is successively visualized after feeding to elimination. Moreover, the particle tracking velocimetry in the chyme leads our quantitative understanding of outstanding mixing and pumping functions in the anterior and posterior intestines by adopting physical parameters of diffusivity and pressure rise, respectively. From scaling analysis, we found that the anterior intestine maintains mixing for 5 h from feeding, whereas the posterior intestine activates gradually pumping up. These results suggest that time change of pumping and mixing functions of intestinal peristalsis could considerably influence the nutrient uptake and microbiotic circumstance in the larval fish intestine.NEW & NOTEWORTHY Transport in gut is important, not only for digestion, metabolism, and nutrient uptake, but also for microbiotic circumstance; however, hydrodynamic effects in the intestine have not been fully clarified. We provide the first quantitative evidence of the mechanical roles of anterograde and retrograde intestinal peristalses in the larval fish of Danio rerio by adopting physical parameters of diffusivity and pressure rise. The intestine transitionally regulates mixing and pumping functions by peristaltic propagations after feeding.

Statistical Analysis of the Mathematical Model of Entropy Generation of Magnetized Nanofluid

This investigation introduces a mathematical model of entropy generation for Magnetohydrodynamic (MHD) peristaltic wave of nanofluid. The governing equations have been created by the supposition of low Reynolds number and long wavelength estimation. The scientific arrangement has been procured with the help of perturbation technique. The concentration profile, temperature profile, pressure distribution and friction forces are shown graphically for some important parameters. Further, the eventual outcomes of connection between the entropy generation and some various parameters have been plotted by means of correlation and regression. It is fundamental to find the affectability of each parameter on entropy generation.

The study of non-Newtonian nanofluid with hall and ion slip effects on peristaltically induced motion in a non-uniform channel

In this study, we considered the unsteady peristaltic motion of a non-Newtonian nanofluid under the influence of a magnetic field and Hall currents. The simultaneous effects of ion slip and chemical reaction were also taken into consideration. The flow problem was suggested on the basis of the continuity, thermal energy, linear momentum, and nanoparticle concentration, which were further reduced with the help of Ohm's law. Mathematical modelling was executed using the lubrication approach. The resulting highly nonlinear partial differential equations were solved semi-analytically using the homotopy perturbation technique. The impacts of all the pertinent parameters were investigated mathematically and graphically. Numerical calculations have been used to calculate the expressions for the pressure increase and friction forces along the whole length of the channel. The results depict that for a relatively large value of the Brownian parameter, the chemical reaction has a dual behaviour on the concentration profile. Moreover, there is a critical point of the magnetic parameter at which the behaviours of the pressure increase and friction forces are reversed for progressive values of the power law index. The present investigation provides a theoretical model that estimates the impact of a wide range of parameters on the characteristics of blood-like fluid flows.

In this study, we considered the unsteady peristaltic motion of a non-Newtonian nanofluid under the influence of a magnetic field and Hall currents.

Peristaltic transport of a MHD Carreau fluid in a tapered asymmetric channel with permeable walls

The effect of permeable walls and magnetic field on the peristaltic flow of a Carreau fluid in a tapered asymmetric channel is studied. The tapered asymmetric channel is normally created due to the intra-uterine fluid flow induced by myometrial contractions and it was simulated by asymmetric peristaltic fluid flow in a two-dimensional infinite non-uniform channel. The analysis has been performed under long wavelength and low-Reynolds number assumptions to linearize the governing flow equations. A series solution in respect of a small Weissenberg number is obtained for the stream function, axial pressure gradient and shear stress. Time average of pressure rise and frictional force on the upper wall has also been computed using numerical integration. The results have been presented graphically for the various interested physical parameters. It is observed that for Carreau fluids the peristalsis works as a pump against a greater pressure rise compared with a Newtonian fluid, while there exists no significant difference in free pumping flux for Newtonian and Carreau fluids in the tapered asymmetric channel.

Influence of Heat Source, Thermal Radiation, and Inclined Magnetic Field on Peristaltic Flow of a Hyperbolic Tangent Nanofluid in a Tapered Asymmetric Channel

In the present analytic thinking, we have modeled the governing equations of a two dimensional peristaltic transport of a Hyperbolic tangent nanofluid in the presence of a heat source/sink with the combined effects of thermal radiation and inclined magnetic field in a tapered asymmetric channel. The propagation of waves on the non-uniform walls to have different amplitudes and phase but the same wave speed is produced the tapered asymmetric channel. The equations of dimensionless temperature and nanoparticle concentration are solved analytically under assumptions of long wavelength and low Reynolds number. The governing equations of momentum of a hyperbolic tangent nanofluid for the tapered asymmetric channel have also been solved analytically using the regular perturbation method. The expression for average rise in pressure has been figured using numerical integrations. The effects of various physical parameters entering into the problem are discussed numerically and graphically. The phenomenon of trapping is also investigated. Furthermore, the received results show that the maximum pressure rise gets increased in case of non-Newtonian fluid when equated with Newtonian fluid.

Peristaltic flow in a tapered channel: application to embryo transport within the uterine cavity

Cyclic uterine peristalsis plays a central role in assisting the transport of sperm to the fallopian tube and later in the conception process in transporting the embryo to a fundal site for implantation. Fulfillment of these essential events within the time limits of fertilization and implantation depends on concomitant intrauterine fluid motion induced by uterine wall motility. A model of wall-induced fluid flow within a finite tapered two-dimensional channel was developed to simulate intrauterine fluid flow pattern and transport phenomena due to symmetric and asymmetric wall displacements. The analysis showed that the transport phenomena are strongly dependent on the phase shift of wall displacement and the angle between the walls. The velocities, flow rates, pressure and the axial transport of massless particles are reduced to zero when contractions are completely out of phase. Cases of reflux and trapping in a tapered channel are discussed for the first time. The reflux phenomenon is most likely to occur when wall motility is asymmetric, especially when the angle between the walls increases, while trapping is enhanced as the asymmetric motility and the angle between the channel walls decrease. The relevance of the results to intrauterine fluid transport phenomena, embryo transfer and hydrosalpinx was explored.

Effects of peristaltic and longitudinal wave motion of the channel wall on movement of micro-organisms: application to spermatozoa transport

A mathematical model is presented to study the motion of the spermatozoa in the cervical canal by considering the transverse waves along its tail and the transverse and longitudinal motions of the cervical wall. In an attempt to control fertility by reducing the speed of sperm, the transverse waves have been considered in the direction opposite to the motion of the spermatozoa. It has been shown that by having appropriate transverse wave motion and longitudinal velocity, the sperm may not be able to move towards the oviduct even if it could continue to have its own propelling velocity. A particular case of the motion of a thin plane sheet in a channel under peristaltic motion of its walls has also been obtained and studied.

Peristaltic transport of a non-Newtonian fluid: applications to the vas deferens and small intestine

The problem of peristaltic transport of a non-Newtonian (Power law) fluid in a uniform and non-uniform tube has been investigated under zero Reynolds number and long wavelength approximation. A comparison of the results with those of Newtonian fluid model shows that the magnitude of pressure rise, under a given set of conditions, is smaller in the case of non-Newtonian fluid, when the flow behavior index n less than 1, at zero flow rate. Further, the pressure rise decreases as n decreases from 1, at zero flow rate, is independent of n at a certain value of flow rate, and increases if flow rate exceeds further. Also, at a given flow rate, an increase in the wavelength leads to a decrease in pressure rise and increase in the influence of non-Newtonian behavior. Pressure rise, in the case of non-uniform geometry, is found much smaller than the corresponding value in the case of uniform geometry. Finally, the analysis has been applied and compared with observed flow rates in the vas deferens in rhesus monkeys and in the small intestine.

Peristaltic transport of blood: Casson model--II

The problem of peristaltic transport of blood in a uniform and non-uniform tube has been investigated, under zero Reynolds number and long wavelength approximation. Blood is represented by a two-layered fluid model consisting of a central layer of suspension of all erythrocytes, etc., assumed to be a Casson fluid, and a peripheral layer of plasma as a Newtonian fluid. A comparison of results with those without peripheral layer shows that the magnitude of the pressure rise, under a given set of conditions is smaller in the case of model with peripheral layer. It is found that, for a given flow rate, the pressure rise decreases as the viscosity of the peripheral layer decreases, and for a given non zero pressure drop, the flow rate increases as the viscosity of the peripheral layer decreases. However, the flow is independent of the presence of the peripheral layer, for zero pressure rise. Further, the pressure rise in the case of non-uniform geometry is found much smaller than the corresponding value in the uniform geometry.

Peristaltic transport of a two-layered model of physiological fluid

The problem of peristaltic transport of a two-fluid (peripheral and core fluid) model in a non-uniform tube and channel has been investigated under long wavelength approximation. A comparison of these results with those for without peripheral layer fluid shows that the magnitude of the pressure rise under a given set of conditions is smaller in the case of with peripheral layer fluid. For a given non zero pressure drop, the flow rate increases as the viscosity of the peripheral layer fluid decrease. However, for zero pressure drop, the flow rate is independent of the presence of peripheral layer fluid. Pressure rise in the case of non-uniform geometry is found to be much smaller than the corresponding values in the case of uniform geometry. The analysis has been applied and compared with the observed flow rates of spermatic fluid (semen) in vas deferens of rhesus monkeys and to the experimental results of Weinberg et al. (1971).