Experimental investigation on thermo hydraulic performance of ferronanofluid flow in a dimpled tube under magnetic field effect

Abstract

Active and passive techniques have been utilized together to enhance heat transfer in this study. The ferronanofluid, magnetic field, and dimpled tube have not been utilized together in the literature so far. Regarding this issue, this investigation is the first experimental study to specify the effect of use of these three effects simultaneously. The concept of this study is to determine the thermo-hydraulic performance of Fe3O4/H2O flow inside a dimpled tube under magnetic field effect. Constant and uniform heat flux of 4500 W/m2 has been applied on the surface of the tube. The work aims to gain data in the range of laminar flow (1131≤ Re≤2102) in the dimpled tube. Dimple geometry with pitch ratio of P/d = 3.75, magnetic field (B = 0.03 ≤ T ≤ 0.16), and nanoparticle volume fraction of 1.0% are the base variables. The results showed that Nusselt number increases with increasing Reynolds number and magnetic field intensity. The highest increase in Nusselt number is obtained as 115.31% compared with the distilled water flow in the smooth tube for the case of magnetic field intensity of 0.3 T. The highest Performance Evaluation Criteria value is also determined as 1.44 for the case of ferronanofluid flow in dimpled tube at Re = 1131 in absence of magnetic field.