Magnetocontrollable convective heat transfer of nanofluid through a straight tube

Currently, nanofluids have been used in the energy conversion process because of their superior optical property and high thermal conductivity. Nanofluids with controllable heat transfer are superior for the tuning the heat transfer speed and efficiency. Herein, we report a method for magnetically increasing heat transfer for use with magnetic nanofluids in a straight tube. Convective heat transfer simulations were performed and the results were found to be consistent with experimental results. The heat exchange performance of magnetic nanofluids were compared with based fluid, and the analysis of heat transfer on magneto-hydrodynamics is presented. Moreover, the effects of Reynolds number, magnetic field horizontal distances, rotation angles and strengths are investigated on the convective heat transfer performance under various magnetic fields. Compared to conventional forced convective heat transfer, the magnetically enhanced heat transfer strategy extends the heat transfer thresholds efficiency and provides more accurate heat transfer enhancement. The effect of magnetic field on heat transfer characteristics occurs in a local area rather throughout tube. The average heat transfer efficiency is increased by 12.2% while the local heat transfer efficiency can be improved more than 30.2% under an applied magnetic field. These results illustrate an advanced method for controlling convective heat transfer by regulating a magnetic field.