Wire Coating Analysis in MHD Flow and Heat Transfer of a Radiative Third Grade Fluid with Variable Viscosity in a Porous Medium

Abstract

Wire coating process is a continuous extrusion process for primary insulation of conducting wires with molten polymers for mechanical strength and protection in aggressive environments. In the present study wire coating is performed using radiative melt polymer satisfying third grade fluid model. The novelty of this study is to analyze the effect of porosity, thermal radiation parameter and varying temperature dependent viscosity on the wire coating. Reynolds Model and Vogel’s Model have been considered to account for temperature dependent viscosity. The equations characterizing the flow and heat transfer phenomena are solved numerically by fourth order Runge-Kutta method and the effects of pertinent parameters are shown with the help of graphs. It is interesting to remark that an increase in non-Newtonian parameter increases the velocity in the absence of porous matrix which coincides with the results reported earlier but in the presence of porous matrix the velocity decreases in the entire span of the flow domain. It is also interesting to note that increase in thermal radiation parameter accelerates the process in the presence of porous matrix. Further, the flow instability in the flows of extrusion die is well marked in case of Vogel’s model as pointed out by Nhan-Phan-Thien.