Impact of cavity tilt angle and magnetic field on the entropy generation of Cu/water nanofluid in a rectangular cavity in the presence of several constant-temperature obstacles

Abstract

This article examines the convection heat transfer (CHT) of Cu/water nanofluid in a cavity with five high-temperature obstacles. The cavity has a low-temperature moving wall (top wall) and three insulated walls. There is a magnetic field (MGD) close to the cavity. The effect of MGD strength for the Hartmann number (Ha) range of 0 to 40 and the tilt angle range of 0 to 90° on heat transfer (HTR) is evaluated. Also, the impact of these variables on thermal entropy generation (EGN), frictional EGN, and Bejan number (Be) is examined. A FORTRAN code has been developed for the simulations, and the Lattice Boltzmann method (LBM) is used in the numerical solution. The results of this study demonstrate that changing the angle of the MGD has little effect on the Nusselt number (Nu). Up to 8% change in the Nu is seen with the tilt angle change. The maximum and minimum values of the Nu are observed at the tilt angles of 0 and 30°, respectively. As the tilt angle approaches 45°, the EGN is reduced. The field angle of 60° corresponds to the maximum EGN. An increment in the strength of the MGD reduces the EGN, average Nu, and Be in such a way that the enhancement in the Ha from 0 to 40 reduces the Nu, EGN, and Be by 41.9%, 21.8%, and 15.2%, respectively.