CFD simulation of the effect of magnetic field on convective heat transfer and ferrofluid flow inside a pipe

Today, one of the best methods to improve heat transfer is using ferrofluid under the effect of a magnetic field. Ferrofluid is a stable suspension containing magnetic nanoparticles and a base fluid that nanoparticles has a higher heat conductivity than the base fluid. In this study, CFD simulation of the effect of a constant magnetic field on the heat transfer rate in the water-Fe3O4 ferrofluid flow in a circular tube under constant heat flux was performed. The simulation was performed in two parts, including the absence of the magnetic field and in the presence of the magnetic field by applying a constant heat flux to the pipe wall. The results showed that the presence of magnetic nanoparticles in water in the absence of magnetic field leads to increasing heat transfer between the tube wall and the fluid. In addition, the presence of nanoparticles in the base fluid increases the Nusselt number compared to pure water. Moreover, applying magnetic field on the tube wall greatly increased the rate of heat transfer to the ferrofluid due to the creation of secondary flows. Finally, the CFD simulation results were compared to the experimental results in a reference and well agreement was seen.