Experimental and numerical investigation of parameters influencing anisotropic thermal conductivity of magnetorheological fluids

Application of a magnetic field causes significant changes in rheological and thermal properties of a magnetorheological (MR) fluid. One of the thermal properties of a MR fluid which is influenced by the magnetic field is the thermal conductivity. In this paper, Discrete Phase Model (DPM) was used to simulate the effects of influencing parameters on thermal conductivity of MR fluids. In the next step, CFD simulation results are validated with experimental data from THW method, and then the effects of influencing parameters on thermal conductivity of MR suspensions are studied. A MR fluid with volume fraction of dispersed carbonyl iron particles equal to 15% in the magnetic field with intensity of 14 mT is tested and it was concluded that in case of a magnetic field is parallel to the temperature gradient direction, the thermal conductivity increases 105%, but if the magnetic field direction is perpendicular to the temperature gradient direction, it decreases by 23%. Results also show that anisotropic thermal conductivity of the MR fluid under investigation is promoted by increasing the volume fraction and decreasing the size of dispersed particles.