Dissipative particle dynamics simulation for the microstructures of ferromagnetic fluids

The three-dimensional (3D) microstructures of ferromagnetic fluids at equilibrium state are simulated using the dissipative particle dynamics (DPD)-based method. First, for the fixed magnetic particle volume fraction phi = 0.1, the microstructures of ferromagnetic fluids are simulated by investigating the influence of the magnetic particle-particle interaction strength on the aggregate structures of ferromagnetic particles. The obtained microstructures of ferromagnetic fluids agree qualitatively with those obtained by molecular dynamics and Monte Carlo simulations in the literature, respectively. Second, for the fixed magnetic particle-particle interaction strength lambda = 5, the influence of the magnetic particle volume fraction on the microstructures of ferromagnetic fluids is investigated. The corresponding radial distribution functions and the time evolution of the mean equilibrium temperature of the magnetic fluid system are also calculated, which shows the correctness of the simulated microstructures. The simulated microstructures of ferromagnetic fluids are in qualitatively good agreement with those obtained by the molecular dynamics method in the literature. In addition, the mean equilibrium velocities of ferromagnetic and dissipative particles are also calculated, and the numerical solutions highly approach the corresponding theoretical values. All the calculations show the correctness of the simulated microstructures of ferromagnetic fluids and verify the validity of the employed DPD-based method. Our results should be of value to study the optical characteristics of ferromagnetic fluids.