A note of the fundamental dynamical flow characteristics of magnetic fluids. Comparison between simple shear and constant pressure gradient flows

When a homogeneous magnetic field is applied parellel to the flow direction, physical quantities such as velocity, angular velocities of fluid and suspended particles, shear stress and pressure are theoretically obtained for two fundamental magnetic fluid flows i.e., a simple shear flow and a constant pressure gradient flow between two parallel plates, under the consideration of the diffusion effect of internal angular momentum on the basis of governing equations for a magnetic fluid, in which is used the constitutive equuation of magnetization proposed by the authors in the previous report. The fundamental dynamical flow characteristics of a magnetic fluid are comprehensively clarified by investigation of the differences which some dimensionless numbers (micropolar effect parameter, magnetic effect parameter, size effect parameter and so on) have on these two kinds of flow. Furthermore a limit of range for the wall surface coefficient when the applied magnetic fields exist is given.