COMPUTATION OF EYRING-POWELL MICROPOLAR CONVECTIVE BOUNDARY LAYER FLOW FROM AN INVERTED NON-ISOTHERMAL CONE: THERMAL POLYMER COATING SIMULATION
B. Md. Hidayathulla Khan, S. Abdul Gaffar, O. Anwar Bég, Ali Kadir, P. Ramesh Reddy
Abstract
Thermal coating of components with non-Newtonian materials is a rich area of chemical and process \nmechanical engineering. Many different rheological characteristics can be simulated for such coatings with a \nvariety of different mathematical models. In this work we study the steady-state coating flow and heat transfer \nof a non-Newtonian liquid (polymer) on an inverted isothermal cone with variable wall temperature. The \nEringen micropolar and three-parameter Eyring-Powell models are combined to simulate microstructural and \nshear characteristics of the polymer. The governing partial differential conservation equations and wall and free \nstream boundary conditions are rendered into dimensionless form and solved computationally with the KellerBox finite difference method (FDM). Validation with earlier Newtonian solutions from the literature is also \nincluded. Graphical and tabulated results are presented to study the variations of fluid velocity, micro-rotation \n(angular velocity), temperature, skin friction, wall couple stress (micro-rotation gradient) and wall heat transfer \nrate. With increasing values of the first Eyring-Powell parameter temperatures are elevated, micro-rotation is \nsuppressed and velocities are enhanced near the cone surface but reduced further into the boundary layer. \nIncreasing values of the second Eyring-Powell parameter induce strong flow deceleration, decrease temperatures \nbut enhance micro-rotation values. An increase in non-isothermal power law index suppresses velocities, \ntemperatures and micro-rotations i.e. all transport characteristics are maximum for the isothermal case (n =0). \nIncreasing Eringen vortex viscosity parameter significantly enhances temperatures and also micro-rotations. The \npresent numerical simulations find applications in thermal polymer coating operations and industrial deposition \ntechniques and provide a useful benchmark for more general computational fluid dynamics (CFD) simulations.