Numerical study on heat generation/absorption effects with activation energy and chemical reaction in tetrahedral nanoparticle flow between two orthogonal porous disks

Nanoparticles play a crucial role in enhancing thermal management, biomedical applications, and advanced industrial processes. This study presents a detailed numerical analysis of heat and mass transfer in a reactive nanofluid containing tetrahedral nanoparticles (aluminum oxide, copper, iron oxide, and titanium oxide), flowing between two orthogonally arranged porous disks. The investigation incorporates the effects of heat generation/absorption, the Cattaneo–Christov heat flux model, activation energy, chemical reactions, and three nanoparticle shapes: spherical, brick, and platelet. Furthermore, the roles of nanolayer thermal conductivity, viscous dissipation, and Joule heating in the heat transfer process are thoroughly examined. The governing nonlinear partial differential equations are transformed into ordinary differential equations using similarity transformations and are solved numerically using the shooting method combined with the fourth-order Runge–Kutta technique. The graphical results are generated using Mathematica software. The findings reveal that the platelet-shaped nanoparticles exhibit significantly superior heat transfer performance, particularly in the suction case, as indicated by higher Nusselt number values compared to other shapes. Increasing the nanolayer thickness enhances the heat transfer rate in both injection and suction scenarios. However, a larger nanoparticle radius leads to opposite fluid behavior in suction and injection cases, as reflected in the Nusselt number values for the lower disk. Moreover, increasing the expansion ratio and magnetic field parameters reduces the radial velocity profile in the central region between the disks but enhances it within the momentum boundary layers near both porous surfaces. Higher values of heat generation or absorption lead to a reduction in the temperature profile, while an increase in activation energy improves mass transfer, as evident from the concentration profile.