Electro-magneto-hydrodynamic flow of couple stress nanofluids in micro-peristaltic channel with slip and convective conditions

K Ramesh,M G Reddy,B Souayeh

doi:10.1007/s10483-021-2727-8

Abstract

This study explores the effects of electro-magneto-hydrodynamics, Hall currents, and convective and slip boundary conditions on the peristaltic propulsion of nanofluids (considered as couple stress nanofluids) through porous symmetric microchannels. The phenomena of energy and mass transfer are considered under thermal radiation and heat source/sink. The governing equations are modeled and non-dimensionalized under appropriate dimensionless quantities. The resulting system is solved numerically with MATHEMATICA (with an in-built function, namely the Runge-Kutta scheme). Graphical results are presented for various fluid flow quantities, such as the velocity, the nanoparticle temperature, the nanoparticle concentration, the skin friction, the nanoparticle heat transfer coefficient, the nanoparticle concentration coefficient, and the trapping phenomena. The results indicate that the nanoparticle heat transfer coefficient is enhanced for the larger values of thermophoresis parameters. Furthermore, an intriguing phenomenon is observed in trapping: the trapped bolus is expanded with an increase in the Hartmann number. However, the bolus size decreases with the increasing values of both the Darcy number and the electroosmotic parameter.

Highlights

Afifi and Gad[28] employed a mathematical model based on a viscous incompressible fluid flow between infinite parallel walls to analyze the peristaltic motion with a porous medium
This section is focused on the influence of various quantities on the axial velocity u, the nanoparticle temperature θ, the nanoparticle concentration σ, the skin-friction coefficient Cf, the nanoparticle heat transfer coefficient N u, the nanoparticle concentration coefficient Sh, and the trapping phenomenon
This is due to the electrical double layer (EDL) effect, and the EDL acts as a resistive agent for the fluid flows

Summary

Introduction

Peristalsis is a systematic mechanism for carrying and moving fluids. This mechanism is based on the relaxation and contraction of waves in the channel containing the fluid. Hlew et al.[15] started working on some physiological transport phenomena by studying fluid propulsion by peristalsis of the small intestine For this purpose, a mathematical model was developed for a viscous fluid in a tube geometry. The effects of MHD, Joule heating, and wall characteristics on the peristaltic flow of nanoliquids were studied by Hayat et al.[48]. Among the previous studies mentioned above, there have been no studies addressing the simultaneous influences of magnetic and electrical fields of couple stress nanofluids in microperistaltic channels under convective and slip boundary conditions with the Runge-Kutta integration scheme To fill this gap, we propose a new model to discuss the propulsion of couple stress nanofluids through peristaltic micro-channels. The consequences of pertinent factors on the characteristics of flow, such as nanoparticle concentration and heat and mass transfer coefficients, are presented

Mathematical modeling

Electro-hydrodynamics

Boundary conditions and volumetric flow rate

Results and discussion

Conclusions