Rheological Effects Due to Oscillating Field on Time Dependent Boundary Layer Flow of Magnetic Nanofluid Over a Rotating Disk

Abstract

This study presents the rheological effects on unsteady flow of an incompressible, electrically non-conducting magnetic nanofluid due to an oscillating magnetic field. Shliomis theory has been employed to formulate the governing equations for nanofluid flow due to a disk rotation. The governing nonlinear coupled partial differential equations with the boundary conditions are transformed into a set of ordinary differential equations which are then solved by Newton’s method in MATLAB. The influences of low oscillating field with different values of effective magnetization parameter and nanoparticle-size volume fraction on the velocity profiles are computed. It has been observed that the effective magnetization parameter creates an additional resistance on the axial velocity provided the applied magnetic field and vorticity of the flow are not collinear. This additional resistance becomes maximal when the applied magnetic field is perpendicular to the vorticity of the flow. Further, the axial velocity depends on the distance from the plate and not on the distance from the axis. The results are very useful in understanding the effects of viscosity variation due to the applied magnetic field and volume fraction on magnetic nanofluid based electronic devices such as damping systems, and needs further practical investigations.