Heat transfer through convection in a quasi-one-dimensional magnetic fluid

Abstract

A magnetic fluid consists of magnetic nanoparticles suspended in nonmagnetic solvent. The buoyancy-induced natural convection is observed in a quasi-one-dimensional magnetic fluid in a horizontal temperature gradient. The local temperatures across the sample were measured by eight thermal sensors in the sample cell in both zero field and as a function of applied field, which is perpendicular to the gravity. In applied magnetic field and field gradient, it was found that when the field gradient is anti-parallel to the temperature gradient the temperature difference across the whole sample, ∆T, increases with increasing field and field gradient, indicating the slowing down of the convective heat transfer. ΔT decreases for field gradient parallel to the temperature gradient, suggesting the speeding up the heat transfer process. We will discuss the possible mechanism for these phenomena. The potential applications in controlling heat transfer in fluids with applied fields will be discussed.