Homotopy Analysis of Activation Energy and Ohmic Heating Effects on Chemically Reacting Magnetohydrodynamic Non-Newtonian Micropolar Fluid Flow over a Stretching Surface
Liberty Ebiwareme
*
Department of Mathematics, Rivers State University, Port Harcourt, Nigeria.
Kubugha Wilcox Bunonyo
Department of Mathematics/Statistics, Federal University, Otuoke, Nigeria.
Obinna Nwokorie
Department of Mathematics, Rivers State University, Port Harcourt, Nigeria.
Fun-Akpo Pere Kormane
Department of Civil Engineering, Rivers State University, Port Harcourt, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The combined effects of activation energy and Ohmic heating on chemically reacting magnetohydrodynamic (MHD) non-Newtonian fluid flow across a stretching surface are thoroughly examined in the manuscript. The fluid behavior is modelled using an appropriate non-Newtonian constitutive relation, while the influence of a transverse magnetic field is incorporated to capture realistic electromagnetic interactions. The heat and mass transfer characteristics are examined by accounting for Ohmic heating and chemical reactions with activation energy, thereby enhancing the physical relevance of the model for industrial and engineering applications. The governing nonlinear partial differential equations are transformed into a coupled system of nonlinear ordinary differential equations via suitable similarity transformations. Semi-analytical Homotopy Analysis Method and MAPLE software were used to achieve a convergent solution and accuracy through optimal auxiliary parameters. A detailed parametric study elucidates the influence of key dimensionless parameters, including Hartmann number, activation energy parameter, chemical reaction rate, Ohmic heating parameter, Prandtl number, Schmidt number, Eckert number, temperature difference parameter, porosity parameter, Micropolar parameter, and spin-gradient viscosity parameter on velocity, temperature, and concentration distributions. The study reveals that higher M, EC, and \(\delta\)increase temperature, while larger Pr and Sc reduce thermal and concentration layer thickness. Increasing \(\lambda\) lowers concentration, and Da decreases velocity in porous media. The micropolar parameters \(\zeta\) and \(\beta\) govern momentum–microrotation coupling. Overall, electromagnetic, chemical, and microstructural effects significantly influence flow, heat, and mass transfer characteristics.
Keywords: Micropolar fluid, magnetohydrodynamics, activation energy, ohmic heating, homotopy analysis method