Numerical simulation method of microstructure and optical characteristics of magnetic fluids

A magnetic fluid possesses a variety of unique characteristics because of both the magnetism of nanoparticles material and the fluidity of the carrier liquid. The characteristics of magnetic fluid depend upon the microstructure of the magnetic nanoparticles aggregation. This paper aims to use the molecular dynamic method to simulate the microstructure formation in a magnetic fluid. A number of inner and external potentials and forces acting on the magnetic fluid are included to reveal the effects of these potentials and forces to the magnetic fluid morphology. Further, a numerical method to study the optical feature of the magnetic fluid films is developed with the Monte Carlo method based on the simulated microstructures, which tracks the spread process of ray transmitting through the magnetic fluid film and computes the spectral transmittivity of the magnetic film. Some factors of affecting the spectral transmittivity of magnetic fluid film are investigated, such as the film thickness, the concentration and diameter of magnetic nanoparticles, and strength of externally applied magnetic field. By combining the molecular dynamic simulation and the ray-tracing method, this paper provides a useful tool for investigating the morphology and optical characteristic of a ferrofluid film.