Thermally developing combined electroosmotic and pressure-driven flow of nanofluids in a microchannel under the effect of magnetic field. (14th April 2015)

• Record Type: Journal Article
• Authors: Ganguly, Suvankar; Sarkar, Sandip; Kumar Hota, Tapan; Mishra, Manoranjan
• Is Part Of: Chemical engineering science. Volume 126(2015)
• Page Start: 10
• Page End: 21
• Publication Date: 2015-04-14
• Subjects: Microchannel -- Nanoparticle -- Solutions -- Magnetohydrodynamics -- Heat transfer; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2014.11.060
• Languages: English
• ISSNs: 0009-2509

Abstract

Abstract: In the present study, the heat transfer characteristics of thermally developing magnetohydrodynamic flow of nanofluid through microchannel are delineated by following a semi-analytical approach. The combined influences of pressure-driven flow, electroosmotic transport and magnetic field is taken into account for the analysis of the complex microscale thermal transport processes. Solutions for the normalized temperature distributions and the Nusselt number variations, considering the simultaneous interplay of electrokinetic effects (electroosmosis), magnetic effects, Joule heating and viscous dissipation are obtained, for constant wall temperature condition. Particular attention is paid to assess the role of nanofluids in altering the transport phenomena, through variations in the effective nanoparticle volume fractions, as well as the aggregate structure of the particulate phases. It is observed that magnetohydrodynamic effect reduces advective transport of the liquid resulting in gradual reduction of heat transfer. Increase in nanoparticle volume fraction shows decrease in heat transfer. Similar effects are observed with increase in aggregate sizes of the nanoparticles. The effect of the nanofluids on system irreversibility is also studied through entropy generation analysis due to flow and heat transfer in the microchannel. Total entropy generation is found to be dominant at the thermally developing region of the microchannel, whereas it drops sharply at the thermally developed region. Presence of nanoparticles in the base fluid reduces the total entropy generation in the microchannel, thereby indicating decrease in thermodynamic irreversibility with increasing nanoparticle volume fraction. Graphical abstract: Highlights: We studied thermally developing magnetohydrodynamic flow of nanofluid in a microchannel. Effect of the magnetic field, nanoparticle concentration and agglomeration are investigated. Heat transfer decreases with increase in nanoparticle concentration and agglomeration. Effect of the nanofluid on system irreversibility is also studied.