Design of an Innovative Magnetic-Nanofluid Heat Pipe for Space Applications

The convective heat transfer characteristics of a single-phase ferrofluid flow inside a heated stainless-steel tube, under the effect of a uniform magnetic field is studied. The ferrofluid travels through a heated tube having an internal diameter of 1.5 mm. For a constant Reynolds number of Re=36, and a uniform magnetic field of 700 G, heat flux is quantified using temperature measurements. Joule heating is applied to increase the tube's temperature. Infrared thermography was used to measure the tube's surface temperature. The fluid inlet and outlet temperatures were measured using two K-type thermocouples. Thermal images were recorded using an IR camera and processed using Fluke Software. The experimental results are validated using a theoretical model. Comparison of Nusselt number with and without magnetic field is characterized. It is observed that when the fluid passes under the influence of an external magnetic field, the surface temperature of the tube decreases corresponding to a significant increase in Nusselt number. A maximum of 50 % increment in heat transfer was observed when operated under optimum conditions.