Analysis of heat and mass transfer in MHD micropolar casson nanofluid under variable heat flux and Arrhenius activation energy

This study presents a numerical investigation of stagnation-point flow and transport characteristics of a micropolar Casson nanofluid over a stretching surface under the combined effects of a transverse magnetic field, variable surface heat flux, and Arrhenius-type chemical reaction. Using suitable similarity transformations, the governing nonlinear partial differential equations are reduced to a system of coupled ordinary differential equations and solved via the Chebyshev wavelet method. The influences of key parameters, including the Casson fluid index, magnetic parameter, microrotation factor, variable heat flux coefficient, and activation energy, on velocity, temperature, concentration, and microrotation profiles are examined. The results indicate that increasing the stagnation-point parameter enhances fluid velocity, while a stronger magnetic field suppresses motion due to Lorentz force. Higher activation energy reduces the rate of chemical reaction, leading to increased concentration distribution. The present findings provide useful insights for thermal management, polymer processing, and biomedical flow applications involving complex non-Newtonian nanofluids.