Journal of Non-Newtonian Fluid Mechanics, Vol.256, 8-22, 2018
Direct numerical simulation of magnetic particles suspended in a Newtonian fluid exhibiting finite inertia under SAOS
A direct numerical simulation approach is utilized to understand the oscillatory shear rheology of a confined suspension of magnetic chains formed by paramagnetic circular cylinders under the influence of an external magnetic field. The common assumption of gap-spanning chains made in the literature is relaxed in this work, so that a fully suspended (periodic) array of magnetic chains is formed. In this sense, the effective rheological parameters are only influenced through a layer of fluid adjacent to the walls. All tests are conducted at very low but finite particle Reynolds numbers, and typical inertial effects are discussed. The main aim of the present study is to investigate the apparent viscoelasticity of the system as a function of the external magnetic field and frequency of the input strain. This work concentrates on cases with large blockage ratio in order to have pronounced viscoelastic behaviours.