Experimental evaluation of forced convective heat transfer and pressure drop of ferrofluid in a U-shaped tube under variable magnetic field

Subject Areas : Heat Transfer

Ali Eslahchi ¹ , Mohammad Hassan Nobakhti ² , Mohammad Behshad shafii ³ , Mohammad Hosein Dibaei Bonab ⁴

1 - Department of mechanical engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 - Department of mechanical engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
3 - Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
4 - Department of mechanical engineering, Science and Research Branch, Islamic Azad University, Shahrood, Iran

Received: 2020-04-13 Accepted : 2020-08-21 Published : 2020-08-21

Keywords: pressure drop":"", ""."heat transfer":"", ""."Magnetic field":"", ""."U-shaped tube":"", ""."ferrofluid,

Abstract :

In this paper, the hydrodynamic and thermal behavior of 〖Fe〗_3 O_4 ferrofluid flow is experimentally investigated in a horizontal U-shaped copper tube under a magnetic field on a surface. The flow passes through a U-shaped tube, with a uniform heat flux in the lower Reynolds. The aim of this study was to experimentally investigate the effect of each of the parameters of nanoparticle volume percentage, Reynolds number changes, tube curvature bending and the effect of constant and alternating magnetic field on pressure drop and forced convection heat transfer in U-shaped tube. The results show that the most effective factor on pressure drop in U-shaped tube, was the curvature of the pipe to about 72.8% and the most effective factor on increasing heat transfer in U-shaped tube, was the relative increase in the tested Reynolds numbers to about 144% compared to other factors. Therefore, with the introduction of performance index η, the highest performance index to simultaneously control the increase in heat transfer coefficient and pressure drop in the best tested conditions, is reported to be 2.31.