2Applied Energetics and Pollution Laboratory, Department of Mechanical Engineering, University of Mentouri Brothers -Constantine, 25130, Algeria
3Laboratory of Applied Mechanics of New Materials - LMANM, Department of Mechanical Engineering, Faculty of Sciences Technology, University of May 8, 1945 Guelma, 2400, Algeria, Applied Energetics and Pollution Laboratory, Department of Mechanical Engineering, University of Mentouri Brothers -Constantine, 25130, Algeria
4Department of Mechanical Engineering, Faculty of Engineering Construction, Mouloud Mammeri University of Tizi-Ouzou, 15000, Algeria
Abstract
The ever-increasing consumption of limited energy sources has forced researchers and engineers to produce more efficient energy systems in order to use energy sources effectively. Among the existing energy systems, those which are made of corrugated configurations play an important role in heat transfer enhancement in many engineering applications such as heat exchangers, microchannel heat sinks, solar collectors, etc. This paper analyses the influence of an electro-
magnetic field on the hydrodynamic and thermodynamic behaviours of Fe3O4-water flow in a corrugated channel in order optimize its performance. Such analysis has not been thoroughly investigated by other researchers. Three-dimensional numerical modelling was used to conduct this study. It consisted in solving the governing equations for continuity, momentum, and energy using the finite volume method. The following boundary conditions have been imposed in the study: the non-corrugated parts of the channel are thermally insulated, whereas the top and bottom corrugated surfaces receive a uniform heat flux. An external and uniform magnetic field is applied perpendicular to the flow in the corrugated section. This study examines the effects of the magnetic field strength, the Reynolds number (Re), and the nanofluid volume fraction on the channel’s heat transfer performance. The analysis of the results reveals that heat transfer is significantly affected by the magnetic field at low Re numbers (less than 400). The presence of a magnetic field, particularly at B = 300G, prominently features the appearance of eddies at Re = 200 and Re = 400. Entropy generation decreases with increasing magnetic field, which is more evident in the B = 200G and B = 300G cases. The Nusselt number increases by more than 80% with B = 300G at a low Reynolds number (Re = 200). Both the thermal and total exergy destruction decrease as the Reynolds number and magnetic field strengths increase, especially in the cases of Re = 200 and Re = 400 with B = 300G. However, an increase in frictional exergy destruction is observed. The minimum total exergy destruction is achieved at Re = 1200, B = 300 G, and a volume fraction of 2%. The thermal exergy destruction and total exergy destruction in the case of B = 300G decrease by 37% compared to water.
