Research Paper : Finite Element Analysis of Multi Physical Slip Flow and Heat Transfer from a Porous Rotating Disk

R. Bhargava... [et.all];

Rotating disk flows arise in many areas of the electrochemical,
biophysics, renewable energy systems and materials processing industries. Motivated by industrial applications, we examine a complex multi-physical coupled nonlinear heat transfer regime in the vicinity of a rotating disk incorporating thermal radiation, magnetohydrodynamics, and wall slip and variable thermophysical properties. A robust variational finite element method (FEM) solution of the transformed flow equations is obtained.
Extensive discussion of the finite element formulation, convergence and validation is provided. We investigate in detail the influence of thermal radiation-conduction parameter (Nr), magnetohydrodynamic parameter (Nm), slip factor (g, related to Knudsen number), uniform injection parameter (W >0) and temperature difference parameter (e), on the axial,
radial and tangential velocity components and temperature function. The finite element computations show that a rise in hydromagnetic interaction parameter (Nm), decelerates the flow in the radial and tangential directions, whereas it accelerates the axial flow, owing to the fact that the axial orientation of the magnetic field only retards the flow perpendicular to the axial direction. Increasing thermal radiation, as simulated via the
Rosseland radiation-conduction parameter ( Nr) decelerates the axial flow but exerts no tangible effect on the radial and azimuthal flows. Temperature is however strongly increased with increasing Nr. An increase in the wall slip factor value (g), is found to decelerate the radial and azimuthal flow), a trend which is maximized at the surface of the porous disk. Increasing injection (W) at the disk surface serves to accentuate radial and azimuthal (tangential) velocity and also temperature. With a rise in disk cooling (e <0) temperatures in the boundary layer regime are found to increase owing to conduction of heat from the disk to the body of rotating fluid; radial flow is decelerated with
greater disk cooling whereas the tangential flow and axial flow are accelerated. The converse behavior is observed with disk heating (e >0).