Experimental study of magnetic field effect on transient Fe3O4 ferrofluid pool boiling at saturated conditions

Abstract

To meet the demand for coolants with higher heat transfer coefficients, a new fluid known as nanofluid was developed. As research progressed, various nanoparticles were incorporated into nanofluids to enhance their thermophysical and heat transfer properties. Among these, ferrofluids were created by adding ferromagnetic nanoparticles to a base fluid. Due to the unique properties of ferrofluids, one research focus is the impact of magnetic fields on their thermal and heat transfer characteristics. Additionally, transient pool boiling—an essential condition with industrial relevance—has been less studied. This research explores both the effects of magnetic fields and the transient nature of pool boiling. This study compares the outcomes of transient Fe3O4 ferrofluid pool boiling under magnetic field presence and absence conditions. Two circuits were designed and built to test periods of 1, 5, 10, 100, 1000, and 5000 s by controlling the heat flux input to a wire heater. Fe3O4 ferrofluid, a working fluid created using a two-step process, had a volume concentration of 0.01 %. The effect of a magnetic field on transient ferrofluid pool boiling characteristics was studied with two permanent magnets made of ceramic materials. The wire superheat temperatures in the presence of the magnetic field dropped by 1.13, 1.05, and 1.27 times, respectively, throughout periods of 1 s, 100 s, and 5000 s. When compared with situations in which a magnetic field wasn’t there, the existence of a magnetic field showed higher heat transfer coefficient. Nanoparticle deposition was accelerated by a magnetic field and settled with particular behaviour at the wire’s surface.