Eur. Phys. J. Plus (2017) 132: 549
https://doi.org/10.1140/epjp/i2017-11813-1

Regular Article

Physical effect of a variable magnetic field on the heat transfer of a nanofluid-based concentrating parabolic solar collector

¹ Esfarayen University of Technology (EUT), North Khorasan, Iran
² International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, 710049, Xi’an, China

^* e-mail: m.hatami@xjtu.edu.cn

Received: 26 June 2017
Accepted: 29 November 2017
Published online: 28 December 2017

Abstract

In this paper, the physical effect of a variable magnetic field on a nanofluid-based concentrating parabolic solar collector (NCPSC) is demonstrated. A section of reservoir is modeled as a semi-circular cavity under the solar radiation with the magnetic source located in the center or out of the cavity and the governing equations were solved by the FlexPDE numerical software. The effect of four physical parameters, i.e., Hartmann Number (Ha), nanoparticles volume fraction (, magnetic field strength ( and magnetic source location (b, on the Nusselt number is discussed. To find the interaction of these parameters and its effect on the heat transfer, a central composite design (CCD) is used and analysis is performed on the 25 experiments proposed by CCD. Analysis of variance (ANOVA) of the results reveals that increasing the Hartmann number decreases the Nusselt number due to the Lorentz force resulting from the presence of stronger magnetic field.