Abstract
Microscopic particles suspended in a fluid flow experience a fluctuation force caused by thermal agitation of solvent molecules such as the Brownian force. Previous works of the Stokes flow have been often solved in a linear hydrodynamic interaction system with a deterministic non-hydrodynamic force or a stochastic force such as the Brownian force and, hence, the hydrodynamic force has been linearly evaluated for the velocity of the bulk flow at the center of the particle. However, our earlier works showed that the nonlinear hydrodynamic interaction would not be so small when the particle abruptly moves with a rotation. The purpose of this study is to establish the numerical strategy to deal with the nonlinear hydrodynamic force acting on a particle and to give some results of the particle motion with the nonlinear Brownian movement.