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This study assesses the dynamics of electromagnetohydrodynamic (EMHD) flow of couple stress fluid through a circular cylinder. The flow is assumed to be driven by electromagnetic force and applied pressure gradient. A comprehensive theoretical framework is developed to solve the Poisson–Boltzmann equation (under the Debye–Hückel approximation) for the electric potential within the electric double layer and the momentum equation for the fluid flow under suitable boundary conditions. The analytical expressions are obtained for velocity and volume flow rate. It is observed that the present results of the couple stress fluid (CSF) model strongly match with those reported in the literature for a Newtonian fluid. The outcome of our analysis reveals that the velocity accelerates with an increase in couple stress and electric field parameters, while it decreases with Hartmann number in the absence of lateral electric field. The study finds major applications in chemical processing and mixing, development of biochips for drug delivery and biomedical engineering. [ABSTRACT FROM AUTHOR]

This study investigates the thermal characteristics and irreversibility analysis of the combined electro-osmotic and electromagnetic flow of a couple stress fluid through a microfluidic channel with constant wall heat flux boundary condition. The analytical solutions for electromagnetohydrodynamic (EMHD) flow velocity, temperature field and entropy production distribution are obtained using the physically relevant boundary conditions. Results show the effects of several factors, including couple stress parameter, Hartmann number, lateral/transverse electric field parameter and Brinkman number on the temperature transport and entropy generation, particularly, the details of how the temperature, Nusselt number and entropy generation vary with these parameters. The results demonstrate that the entropy generation in the channel is strongly dependent on the flow velocity and thermal energy distribution. In this analysis, the primary focus is placed on the impact of the couple stress parameter on EMHD flow velocity, heat transfer and entropy generation. The results reveal that when the couple stress physical parameter increases, the magnitude of temperature and Bejan number decreases. However, the Nusselt number and entropy production rates have opposite effects towards the channel walls. The present research has enormous practical significance and can design efficient thermal micro/nanoequipment. [ABSTRACT FROM AUTHOR]

Peristalsis is the most dynamic phenomenon that is significant in the biomedical domain and offers considerable promise in microscale fluids. For the past few years, this biomimetic (peristaltic) phenomenon attracted the attention of the research community because of its massive applications in numerous medical and industrial domains. In the present study, the steady, laminar rheology of biological fluid from a biomimetic (peristaltic) channel is considered. The rheological equations are expressed in the Cartesian system, and the porosity effects are modelled (added) on a body force term of the momentum equation. The current analysis depends on the creeping phenomena and long wavelength. The closed-form solutions are acquired by using integration on the rheological equations subject to suitable boundary conditions. The rheology is controlled by two embedded parameters, the porosity and non-Newtonian parameters. It is shown using graphs that the magnitude of axial velocity is strongly affected by the larger strength of porosity (Darcy's number) and non-Newtonian (couple stress) parameters. We noticed the impacts of involved rheological constraints on pumping and trapping phenomena in the light of porous effects. Additionally, the wavy pattern of sinusoidal waves is utilised in the present analysis to increase the efficiency of the peristaltic pump. By increasing the porosity impacts, the magnitudes of velocity profile and pressure gradient of a biofluid are increased. The porosity has a dynamic role in the augmentation of peristaltic pumping. The impacts of couple stress parameter reduces the viscous effects. These outcomes may be useful in bioengineering (drug delivery schemes) and chemical processes. [ABSTRACT FROM AUTHOR]

The present article deals with theoretical analysis on the peristaltic transport of a couple stress fluid with lubrication on the walls of the channel. The walls are coated with thin layer of power-law lubricant and the condition arised by the coating is modelled by taking the continuity of velocity and shear stresses of both the fluids at the fluid–fluid interface. The flow problem is discussed in two-dimensional asymmetric medium assuming long wavelength and low Reynolds number. Closed form solutions for velocity, stream function and flow rate are discussed. The numerical solutions for pressure rise, trapping and reflux are discussed. The effects of lubricant parameter, couple stress parameter, phase difference, wave amplitudes and flow rate are discussed for symmetric and asymmetric channels. It is observed that by increasing the lubrication effects, pressure rise increases in the pumping region and for trapping, boluses disappear and streamlines become parallel to the walls of the channel. From the given flow problem, the limiting cases of no-slip and viscous flow are presumed and found to be in excellent agreement with the existing literature. [ABSTRACT FROM AUTHOR]

A mathematical model is developed to analyse the peristaltic flow of couple-stress fluid in an inclined asymmetric channel with convective conditions. Soret and Dufour and Hall effects are taken into account. Analysis has been carried out in a wave frame of reference. Expressions for velocity, pressure gradient, temperature and concentration are constructed. Pumping and trapping phenomena are examined. Impact of sundry parameters on the velocity, temperature and concentration is discussed. [ABSTRACT FROM AUTHOR]

Radiative–convective flow studies find wide range of applications in furnace design, solar fans, photochemical reactors, turbid water bodies, etc. The present article focusses on unsteady radiative–convective hydromagnetic couple stress fluid (CSF) flow from a vertical cylinder using the thermodynamic concept. The obtained governing equations of the present model are resolved by a well-organised numerical scheme. The unsteady nature of friction, entropy, coefficients of heat and mass transfer (HMT) along with the time-independent state pattern of flow-field profiles, are shown graphically for distinct values of governing radiation parameter, magnetic parameter, concentration parameter, and constant parameter to display important aspects of the solution. To analyse the HMT process in a 2D domain, Bejans flow visualisation is considered along with isotherms, streamlines, and isoconcentration lines. The Bejans HMT flow visualisation shows that the heat and mass function contours are denser in the foremost verge of the hot surface of the cylinder compared to other contours. The result indicates that the entropy generation (EG) parameter increases with decreasing values of radiation and magnetic parameters. Also, the entropy parameter increases for increasing values of concentration parameter or constant parameter. [ABSTRACT FROM AUTHOR]