M.P. Mkhatshwa
This paper presents the parametric and sensitivity-based numerical investigation of magnetically driven natural convective boundary layer flow of Casson hybrid nanofluid through a vertically oriented porous cone with fluctuating nanofluid features, constant wall thermal and mass fluxes, viscous and Ohmic dissipation, radiative heat flux, heat sink/source and chemical reactive species. This work is devoted to comprehending the significance of these factors on the flow fields and contours, momentum, thermal and mass transport features of hybrid nanofluids. The governing equations admit dimensionless form using similarity transformations, and the subsequent transport equations are solved via an overlapping grid multi-domain spectral discretization method. This numerical scheme enables superior accuracy in simulating the behavior of flow and transport processes. Normalized sensitivity indices are used to quantitatively evaluate how key parameters influence the behaviour of the system. Graphs demonstrate that elevating values of fluctuation viscosity, permeability, magnetic field, and Casson fluid parameter diminishes flow velocity and shear stress rate. Superior thermal radiation and variable thermal conductivity enforces fluid temperature and the rate at which heat is transported, while accelerating chemical reaction rate and variable diffusivity enhances species transport rate. Hybrid nanoparticle concentration elevates the Nusselt numbers while reducing skin friction, revealing enhanced thermal transport with reduced flow resistance. Casson-hybrid nanofluid effects promote more pronounced penetration of both streamlines and isotherms, confirming enhanced convection and improved heat transport. Sensitivity analysis emphasizes that quantities of engineering interest are significantly influenced by nanoparticle volume fraction, implying that nanoparticle loading is a dominant control mechanism for transport performance in hybrid nanofluid systems.