Thermal conductivity of flake-shaped iron particles based magnetorheological suspension: Influence of nano-magnetic particle concentration

The non-spherical shape (flake-shape) iron particles based magnetorheological (MR) fluid thermal conductivity is experimentally investigated using the hot-wire method. Under the magnetic field, thermal conductivity is enhanced by 20% compared to spherical shape commercial MR fluid having nearly 20% higher volume fraction of iron particles. This enhancement attributes to the larger contact area of the flake-shape particle (when they form a chain), which helps to transport heat quickly. The magnetic nanoparticles of size 6.5 nm were added to this MR fluid for varying magnetic weight fraction and studied its influence on thermal conductivity. The increase of magnetic nanoparticle concentration enhances the thermal conductivity and increases field reversibility. The observed increase in thermal conductivity and low hysteresis losses is attributed to the friction reduction in flake-shaped iron particles in the presence of nanoparticles. © 2020 Elsevier B.V.