Homotopy simulation of dissipative micropolar flow and heat transfer from a two-dimensional body with heat sink effect : applications in polymer coating

Non-Newtonian flow from a wedge constitutes a fundamental problem in chemical engineering systems and is relevant to processing of polymers, coating systems etc. Motivated by such applications, we employ the homotopy analysis method (HAM) to obtain semi-analytical solutions for thermal convection boundary layer flow of incompressible micropolar fluid from a two-dimensional body (wedge). Viscous dissipation and heat sink effects are included. The non-dimensional boundary value problem emerges as a system of nonlinear coupled ordinary differential equations, by virtue of suitable coordinate transformations. The so-called “Falkner-Skan” flow cases are elaborated. Validation of the HAM solutions is achieved with earlier simpler models and also with a Nakamura finite difference method for the general model. The micropolar model employed simulates certain polymeric solutions quite accurately and features rotary motions of micro-elements. Primary and secondary shear stress, wall couple stress, Nusselt number, micro-rotation velocity and temperature are computed for the effect of vortex viscosity parameter (micropolar rheological), Eckert number (viscous dissipation), Falkner-Skan (pressure gradient) parameter, micro-inertia density and heat sink parameter. The special cases of Blasius and stagnation flow are also addressed. It is observed from the study that the temperature and thermal boundary layer thickness are both suppressed with increasing wedge parameter and wall heat sink effect which is beneficial to temperature regulation in polymer coating dynamics. Further, strong reverse spin is generated in the micro-rotation with increasing vortex viscosity which results in increase in angular momentum boundary layer thickness. Also, primary and secondary skin friction components are both reduced with increasing wedge parameter. Nusselt number is also enhanced substantially with greater wedge parameter