The effects of particle mass fraction and static magnetic field on the thermal performance of NiFe2O4 nanofluid in a heat pipe.

In this study, experimental investigations are performed in order to determine the thermal performance of NiFe 2 O 4 nanoparticles dispersed in deionized water in a thermosyphon-type heat pipe. The effects of the magnetic flux density and nanoparticle mass fraction were analyzed at different heat inputs and cooling water flow rates. The magnetic field was generated by the current-carrying solenoid. Our results indicated that the use of NiFe 2 O 4 nanofluid significantly improves the thermal performance of the heat pipe which also showed that the enhancement of heat transfer coefficient can be obtained with increasing mass fraction and in presence of a low parallel magnetic field. A decrease of 26.6% was achieved in the temperature difference between the evaporator and the condenser regions compared to distilled water at a 3% mass fraction and under a magnetic field. The maximum improvement in heat pipe's thermal resistance was found as 30.4%, through NiFe 2 O 4 nanofluid usage under magnetic field. Compared to base fluid, the application of magnetic nanofluid and parallel magnetic field reduces the thermal resistance, increases heat pipe efficiency and the heat transfer coefficient. [ABSTRACT FROM AUTHOR]