MHD effects on heat transfer and entropy generation of nanofluid flow in an open cavity

• Published in: Journal of magnetism and magnetic materials 2015-01, Vol.374, p.214-224
• Main Authors: Mehrez, Zouhaier, El Cafsi, Afif, Belghith, Ali, Le Quéré, Patrick
• Format: Article
• Language: English
• Subjects: Computational fluid dynamics; Entropy; Entropy generation; Fluid flow; Heat transfer; Magnetic field; Magnetic fields; Mathematical models; Nanofluid; Nanofluids; Nanostructure; Open cavity; Reynolds number
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2014.08.010

The present numerical work investigates the effect of an external oriented magnetic field on heat transfer and entropy generation of Cu–water nanofluid flow in an open cavity heated from below. The governing equations are solved numerically by the finite-volume method. The study has been carried out for a wide range of solid volume fraction 0≤φ≤0.06, Hartmann number 0≤Ha≤100, Reynolds number 100≤Re≤500 and Richardson number 0.001≤Ri≤1 at three inclination angles of magnetic field γ: 0°, 45° and 90°. The numerical results are given by streamlines, isotherms, average Nusselt number, average entropy generation and Bejan number. The results show that flow behavior, temperature distribution, heat transfer and entropy generation are strongly affected by the presence of a magnetic field. The average Nusselt number and entropy generation, which increase by increasing volume fraction of nanoparticles, depend mainly on the Hartmann number and inclination angle of the magnetic field. The variation rates of heat transfer and entropy generation while adding nanoparticles or applying a magnetic field depend on the Richardson and Reynolds numbers. •MHD effects on Cu–water nanofluid flow into an open cavity are studied.•Entropy generation and heat transfer are strongly influenced by the magnetic field.•The effect of nanoparticles volume fraction depends on Hartmann number.•The influence of the magnetic field varies by varying Reynolds and Richardson numbers.