Mesoscopic simulation for the structures of magnetic fluids

Abstract

The microstructures of magnetic fluids are simulated using a dissipative particle dynamics (DPD)-based method and are fundamentally important for controlling the macroscopic properties of magnetic fluids and understanding the corresponding rheological behaviors in diverse engineering applications. The cubic polynomial spline function often used as smoothing function in smoothed particle hydrodynamics (SPH) is employed as the conservative force potential function, which can provide a stronger conservative force weight function than the conventional weight function by choosing properly the cutoff radius between the dissipative particles. By employing the above method, the desired results are obtained for both stronger and weaker magnetic particle-particle interaction under the condition of varying the mass of the dissipative particles. In addition, the influences of the magnetic particle-particle interaction and of the magnetic particle area fraction on the microstructure of magnetic fluids are also investigated, respectively, and the obtained results agree qualitatively well with those in the literature obtained by other numerical approaches and experiments. The numerical solutions of the mean equilibrium velocities of the magnetic and dissipative particles are also calculated and approximate the corresponding theoretical values very well. Therefore the employed DPD-based method is highly effective in the simulation of the microstructure of magnetic fluids.