On Unsteady Three-Dimensional Axisymmetric MHD Nanofluid Flow with Entropy Generation and Thermo-Diffusion Effects on a Non-Linear Stretching Sheet

Mohammed Almakki,Sabyasachi Mondal,Precious Sibanda,Sharadia Dey

doi:10.3390/e19070168

Mohammed Almakki, Sabyasachi Mondal + Show 2 more

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https://doi.org/10.3390/e19070168

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Abstract

The entropy generation in unsteady three-dimensional axisymmetric magnetohydrodynamics (MHD) nanofluid flow over a non-linearly stretching sheet is investigated. The flow is subject to thermal radiation and a chemical reaction. The conservation equations are solved using the spectral quasi-linearization method. The novelty of the work is in the study of entropy generation in three-dimensional axisymmetric MHD nanofluid and the choice of the spectral quasi-linearization method as the solution method. The effects of Brownian motion and thermophoresis are also taken into account. The nanofluid particle volume fraction on the boundary is passively controlled. The results show that as the Hartmann number increases, both the Nusselt number and the Sherwood number decrease, whereas the skin friction increases. It is further shown that an increase in the thermal radiation parameter corresponds to a decrease in the Nusselt number. Moreover, entropy generation increases with respect to some physical parameters.

Highlights

The study of unsteady nanofluid flow, heat and mass transfers along a nonlinear stretching surface has received considerable attention during the last few years because of several applications in engineering processes, such as in materials manufacturing through extrusion, glass-fiber and paper production
The derivation of the quasi-linearization method (QLM) is based on the linearization of the nonlinear components of the governing equations using the Taylor series assuming that the difference between the value of the unknown function is negligible between the current iteration, r + 1, and the previous iteration, r
The spectral quasi-linearization method (SQLM) has been used in a limited number of studies to solve boundary layer flow, heat and mass transfer problems [34]

Summary

Introduction

The study of unsteady nanofluid flow, heat and mass transfers along a nonlinear stretching surface has received considerable attention during the last few years because of several applications in engineering processes, such as in materials manufacturing through extrusion, glass-fiber and paper production. Unsteady mixed convection in boundary layer flows have received attention with a large number of studies focusing on heat and mass transfer characteristics in nanofluids (Dessie et al [1]). Nanofluids have increased thermal conductivity and convective heat transfer performance as compared to base fluids such as water and oils. The notion of a nanofluid was introduced by Choi [2] when he proposed the suspension of nanoparticles in a base fluid like water, oil or an ethylene-glycol mixture. These common base fluids have lower thermal conductivity, which is increased when nanoparticles are added. Nanofluids have been used in applications that require high-performance

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