Control of flow and suppression of separation for Couette-Poiseuille hydrodynamics of ferrofluids using tunable magnetic fields

The present study reports unidirectional laminar flow of ferrofluids between parallel plate channels under the action of a homogeneous magnetic field. The applied field is found to uniquely modify the local velocity distribution and to reduce the effect of both adverse and favorable pressure gradients. We find that it is possible to control the flow separation by varying the magnetic field strength within a certain range of adverse pressure gradients. We also discuss the effect of the magnetization relaxation time scale and volume fraction of the solid magnetic particles on the flow phenomenon. Finally, we propose an analytical solution which provides closed form expressions for velocity and spin field that are in good agreement with the numerically obtained results.