A NEW METHOD TO SIMULATE THE DYNAMICS OF SINGLE FIBER IN COMPLEX FLOW FIELDS
复杂流场中单纤维动力学计算的一种新算法

The translational and rotational dynamics of fibers suspended in a fluid medium are important in many different fields of modem technology. Jeffery derived an equation of motion for a single rigid ellipsoidal particle suspended in Newtonian fluids. Unfortunately, the analytical solutions of Jeffery equation could only be obtained in a simple planar shear flow and a planar elongational flow. The main difficulty in the numerical treatment of Jeffery equation is the singularity due to the term $\cot \theta $. In this paper, a co-rotational coordinate system is proposed, which can completely eliminates this singularity. The validity of the proposed scheme is shown by a comparison between numerical results and the analytical solution. New algorithm can easily be extended to simulate the dynamics of single fiber in complex flow fields.