Electromagnetohydrodynamic Electroosmotic Flow and Entropy Generation of Third-Grade Fluids in a Parallel Microchannel.

Chunhong Yang,Zhiyong Xie,Yongjun Jian,Fengqin Li

doi:10.3390/mi11040418

Chunhong Yang, Zhiyong Xie + Show 2 more

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https://doi.org/10.3390/mi11040418

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Journal: Micromachines	Publication Date: Apr 16, 2020
Citations: 14	License type: CC BY 4.0

Affiliation: Inner Mongolia University

Abstract

The present paper discusses the electromagnetohydrodynamic (EMHD) electroosmotic flow (EOF) and entropy generation of incompressible third-grade fluids in a parallel microchannel. Numerical solutions of the non-homogeneous partial differential equations of velocity and temperature are obtained by the Chebyshev spectral collocation method. The effects of non-Newtonian parameter Λ, Hartman number Ha and Brinkman number Br on the velocity, temperature, Nusselt number and entropy generation are analyzed in detail and shown graphically. The main results show that both temperature and Nusselt number decrease with the non-Newtonian physical parameter, while the local and total entropy generation rates exhibit an adverse trend, which means that non-Newtonian parameter can provoke the local entropy generation rate. In addition, we also find that the increase of non-Newtonian parameter can lead to the increase of the critical Hartman number Hac.

Highlights

Microfluidic devices are widely demonstrated in areas of biomedical and biochemical analysis, and have been one of the powerful tools for studying basic physical processes [1,2,3]
By utilizing the Chebyshev spectral collocation method, we study the non-dimensional EMHD velocity, temperature, Nusselt number and entropy generation of third-grade fluids between two parallel micro-plates, owing to the fact that the analytical solutions of these physical quantities are difficult to obtain for third-grade fluids when EMHD electroosmotic effects are all taken into condition
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Summary

Introduction

Microfluidic devices are widely demonstrated in areas of biomedical and biochemical analysis, and have been one of the powerful tools for studying basic physical processes [1,2,3]. In these processes, pressure gradients, electrical fields, magnetic fields or their suitable combinations are the popular actuation mechanisms. Compared with the previous single pattern of pressure-driven flow, increasing attention has been attached to electroosmotic and electromagnetic actuation mechanisms in recent years. Heat-transfer phenomena that are associated with electroosmotic and pressure-driven flows in microchannels have been studied for thermally fully-developed flows [13,14,15] and thermally developing flows [16,17]

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