Heat Transfer Engineering, Vol.35, No.1, 25-33, 2014
Experimental Investigation of Thermal Resistance of a Ferrofluidic Closed-Loop Pulsating Heat Pipe
For the present article, a pulsating heat pipe (PHP) is fabricated and tested experimentally by bending a copper tube. The effects of working fluid, heat input, charging ratio, inclination angle, magnets location, and ferrofluid (magnetic nanofluid) volumetric concentration have been investigated on the thermal performance of this PHP. Experimental results show that using ferrofluid as a working fluid improves the thermal performance of the PHP significantly. Moreover, applying a magnetic field on a ferrofluidic PHP reduces its thermal resistance. By changing the inclination angle of the PHP from vertical mode to angles close to the horizontal mode, the present PHP has a constant and acceptable thermal performance. Reduction of the magnetic flux density at the evaporator decreases the PHP's thermal performance as well. Increasing the ferrofluid volumetric concentration in the experimental range enhances the thermal performance of the PHP.