STUDY OF THE MAGNETIC TAYLOR-COUETTE FLOW WITH THE AXIAL FLOW IN ROTATING MACHINERY UNDER QUADRUPOLE MAGNETIC FIELD

Abstract

In this study, the effect of applying a magnetic field resulting from quadrupole magnets on the hydrodynamics and heat transfer in magnetic Taylor-Couette flow with axial flow was investigated numerically for the first time. The studied geometry consisted of two vertical concentric cylinders. The inner cylinder rotated at a specific angular velocity to create the Taylor-Couette flow, while the outer cylinder was stationary. The outer cylinder was also considered to be under constant heat flux boundary conditions. The magnetic nanofluid was a water-based nanofluid consisting of iron oxide nanoparticles with diameters of 8 nm and the magnetic field was produced by quadrupole magnets. The modeling of the problem was implemented by using the two-phase mixture model and control volume technique. The obtained results indicated that in the absence of a magnetic field and using our considered range of Taylor numbers, the flow consisted of many vortices, which is called the Taylor vortex flow. By applying the magnetic field, the ferrofluid flow was pushed toward the outer cylinder wall, which also considerably increased the stability of the flow. Moreover, by imposing the magnetic field, the local heat transfer coefficient increased and the heat transfer coefficient decreased as the Taylor number of the flow increased.