強磁場・単純せん断流動場における磁性流体の凝集構造の分類(流体工学, 流体機械)

抄録

Ferrofluids make aggregations under a strong magnetic field. Therefore, the rheological property becomes complex and nonlinear. In this research, the numerical analysis of the aggregation of ferrofluids under the strong uniform magnetic field and simple shear flow field was made by the Stokesian dynamics method. Results obtained are as follows. (1) The aggregate structure can be classified into four types : the cylindrical structure type, the layered structure type, the diagonal structure type and the corrupt structure type. (2) The apparent shear viscosity by magnetic force shows a characteristic peculiar to each aggregate type. (3) The apparent shear viscosity by magnetic force decreases as the shear rate increases. (4) The apparent shear viscosity by magnetic force increases as the saturation magnetization of magnetic particles increases.