Abstract
An interesting phenomenon so called hysteresis in magneto-rheological (MR) fluid appears when a magnetic field is increased to and decreased from a certain value. This phenomenon appears to be caused by the formation of robust clusters in proportion to the magnetic field intensity. Results show that the hysteresis in MR fluid are different in comparison with the magnetic fluid. It seems that cluster formation in the MR fluid breaks more quickly and eventually becomes the same as the initial conditions after the external magnetic field intensity is zero.
