Numerical analysis for magnetic effects on newtonian and non-newtonian ferrofuid flow around a circular cylinder

Abstract

In this study, the e ects of magnetic eld applications are investigated on ferromagnetic ow around cylinder. The analyses are made for Newtonian and non- Newtonian ow types. In order to investigate the non-Newtonian uids, shear thinning and shear thickening models are used in numerical studies. The magnets on the cylinder are located on 90o {u100000} 150o and 210o {u100000} 270o clockwise. All of these three types of uids, whose Reynolds values ranging from 50 to 1500, are experimented to show deviation on the drag coe cient, separation point, wake region and vortex formation length with magnetostatic e ects by means of various tables and graphics. Consequently, the magnetostatic force shows a decreasing e ect on drag coe cient for any type of uid. Drag coe cient becomes higher for shear thickening uid on each Reynolds number; on the other hand, this value for shear thinning uids becomes smaller than that, belongs to Newtonian uid, for smaller Re number cases, and higher for higher Re number cases. Besides, the largest change on drag coe cient is observed on shear thickening uids. Vortex formation length decreases with magnetostatic e ects, although the change is not as high as drag coe cient observations. This value for shear thickening uid becomes higher than values for Newtonian uids for low Re number cases, and lower for high Re number cases. Vortex formation of shear thinning uid is observed as higher than any type of uid. Separation point and wake formation can be observed clearer for higher magnetic force values. Vortex formation length gets also bigger values with magnetic force. When the magnets are placed on the front side, separation point gets on the front side in a clear way and increased the drag coe cient largely.