Rheological properties of ferrofluids with drop-like aggregates

Many experiments demonstrate that dense drop-like aggregates, consisting of tremendous number of magnetic particles, appear in ferrofluids under the action of quite moderate magnetic fields. We present results of theoretical study of influence of these aggregates on macroscopical rheological properties of ferrofluids under assumption that the applied field is parallel to the gradient of shear flow. The results show that the drop-like clusters, elongated along the gradient of flow, induce strong magnetoviscous effects comparable to those observed in experiments.