Oriented magnetic field effect on mixed convective flow of nanofluid in a grooved channel with internal rotating cylindrical heat source

Abstract

In this paper, the flow and heat transfer characteristics for the influence of oriented magnetic field on mixed convection flow of water based nanofluid inside a grooved channel with a rotating heat source are numerically investigated. The channel is cooled from the grooved as well as vertical walls and heated from the bottom walls as well as rotating heat source while the remaining walls are thermally insulted. The channel is permeated by an inclined magnetic field of uniform strength, and a modified model of effective thermal conductivity is used to improve the overall thermal conductivity of nanofluids. The governing partial differential equations representing the flow model are solved with Galerkin weighted residual finite element method. A complete parametric study is carried out based on numerical results to show the variations of flow and temperature fields in terms of streamlines, isotherms, velocity and temperature profiles, average Nusselt number and average temperature for the effects of pertinent parameters including Reynolds number, Hartmann number, volume fraction of nanoparticles and inclination angle of the magnetic field. It is observed that average heat transfer rate enhances noticeably with the increase in Reynolds number and volume fraction and reduces for increasing Hartmann number. It is also found that the augmentation of heat transfer due to higher inclination angle of magnetic field becomes significant when the value of Hartmann number is sufficiently large. Moreover, the effects of governing parameters on the fluid flow and heat transfer behaviors are affected remarkably with the presence of rotating heat source and the direction of rotation as well. Comparisons of the present results with the previous published results are performed and excellent agreement is found. The outcome of this study can be applied to design engineering equipments such as high performance heat exchangers, cooling of electronic devices and circuit boards, cooling of nuclear reactors and biomedical equipments, etc.