Experimental Investigation of Thermal Conductivity of Water-Based Fe(3)O(4) Nanofluid: An Effect of Ultrasonication Time

Nanofluid preparation is a crucial step in view of their thermophysical properties as well as the intended application. This work investigates the influence of ultrasonication duration on the thermal conductivity of Fe [Formula: see text] O [Formula: see text] nanofluid. In this work, water-based Fe [Formula: see text] O [Formula: see text] nanofluids of various volume concentrations (0.01 and 0.025 vol.%) were prepared and the effect of ultrasonication time (10 to 55 min) on their thermal conductivity was investigated. Ultrasonication, up to a time duration of 40 min, was found to raise the thermal conductivity of Fe [Formula: see text] O [Formula: see text] nanofluids, after which it starts to deteriorate. For a nanofluid with a concentration of 0.025 vol.%, the thermal conductivity increased to 0.782 W m [Formula: see text] K [Formula: see text] from 0.717 W m [Formula: see text] K [Formula: see text] as the ultrasonication time increased from 10 min to 40 min; however, it further deteriorated to 0.745 W m [Formula: see text] K [Formula: see text] after a further 15 min increase (up to a total of 55 min) in ultrasonication duration. Thermal conductivity is a strong function of concentration of the nanofluid; however, the optimum ultrasonication time is the same for different nanofluid concentrations.