Carreau hybrid nanofluid flow over a moving wedge with convective heating and zero-flux reactive nanoparticle boundary conditions under MHD and radiative effects

This study presents a numerical investigation of radiative magnetohydrodynamic (MHD) flow of a Carreau hybrid nanofluid over a moving wedge, incorporating coupled momentum, heat, and mass transfer with homogeneous–heterogeneous chemical reactions. The hybrid suspension consists of multi-walled carbon nanotubes (MWCNT) and aluminum oxide ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>Al</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mrow> <mml:mi>O</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> ) dispersed in ethylene glycol, and its shear-dependent behavior is modeled through the Carreau rheological framework to capture elasticity-driven effects. The energy transport equation accounts for Rosseland thermal radiation, Joule heating induced by the applied magnetic field, and internal heat generation/absorption representing endothermic and exothermic processes. A convective boundary condition models finite surface heating, while zero-nanoparticle-flux conditions ensure physically realistic coupling of Brownian motion and thermophoresis. Reactive transport is described through first-order homogeneous reactions in the bulk and heterogeneous catalytic reactions at the wedge surface, with Arrhenius activation energy governing reaction sensitivity. The governing similarity-reduced system of nonlinear ordinary differential equations is solved using the shooting method with a Runge–Kutta Fehlberg (RKF-45) integrator. Validation through benchmark comparisons confirms the accuracy of the numerical strategy. Parametric analysis highlights the interplay between magnetic damping, shear-dependent viscosity, hybrid nanoparticle loading, radiative transport, and surface reactivity. Results reveal that the magnetic field enhances near-wall velocity for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mo>&lt;</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:math> , whereas higher Weissenberg number and Carreau index suppress momentum due to elastic and thickening effects. Temperature rises with increasing radiation, Joule heating, and exothermic heat sources, while activation energy and reaction rate significantly influence species concentrations. The findings offer a unified understanding of electrically conducting Carreau hybrid nanofluids, providing valuable insights for heat management, catalytic processing, and advanced thermal-fluid engineering applications.