Horizontal Magnetic Field Influence on Fluid Flow Across a Variable Thickness Rotating Disk With Stretching and Melting Phenomenon

An incompressible steady-state flow of viscous fluid subjected to a variable thickness rotating surface is examined. The laminar flow stream is also affected by the disk stretching. A horizontal magnetic field is applied along the disk to stabilize the flow dynamics depending on its orientation and strength. The implication of a horizontal magnetic field is also effective in regulating the thermal energy in high-temperature environments such as turbines and nuclear reactors. The thermal features are also characterized by thermal radiation and melting heating. The melting phenomenon is useful in phase-change materials for efficient thermal storage and release like polymer molding or metal casting. Similarity transformations that account for the variable thickness of the disk surface are utilized to dimensionalize the flow equations and to obtain a self-similar solution. The numerical scheme Runge-Kutta-Fehlberg (RKF-45) built-in package is used for the solution of the normalized flow model. The salient nature of the physical parameters is illustrated in the momentum and thermal fields. The numerical data on skin-friction coefficient and local Nusselt number at the stretchable surface is also calculated. The graphical results indicate that the flow and temperature profiles are strongly influenced by the physical parameters under consideration. It can be deduced that melting decreases the fluid resistance close to the surface, reducing drag, and in turn increasing flow velocity. The latent energy absorbed during the melting process reduces the effective thermal energy into the fluid that reduces the temperature gradients in the thermal boundary layer flow. The stabilizing effect of the horizontal magnetic field on the flow phenomenon along the radial direction is observed for the angle ${\alpha }_1$ varying from 0 to 30 degrees. It is seen that the dimensionless radius facilitates the thermal transport phenomenon from the disk surface to the fluid, thus resulting in reduction of the thermal field.