Advanced thermal management for next-generation engineering heat control using magnetized ternary nanofluid transport between two coaxial disks.

This study investigated the three-dimensional magnetohydrodynamic flow and heat transfer of the ternary nanofluid (Cu-Al₂O₃-TiO₂/water) between two coaxial rotating and stretching disks embedded in a porous medium. The model incorporated magnetic field, viscous dissipation, Forchheimer drag, thermal relaxation, disk stretching, and slip boundary conditions to capture realistic flow and thermal behavior. The governing equations are transformed into nonlinear ordinary differential equations via similarity transformations. The semi-analytical solution is obtained using the Homotopy Analysis Method (HAM). COMSOL Multiphysics (FEM) is employed to simulate the full 3D field by validating the analytical result. A parametric study revealed that the ternary nanofluid exhibited superior momentum and heat transfer compared to hybrid and simple nanofluids. Magnetic field and porous drag suppressed velocities but enhanced thermal accumulation, whereas disk rotation and stretching amplified both velocity and Nusselt number. Slip parameters reduce skin friction and heat transfer, while the Eckert number increases flow resistance and temperature. Excellent agreement between HAM and COMSOL confirmed the reliability of the solutions. The findings provide valuable guidelines for enhanced thermal management in industrial and electronic systems, and the study presented a novel analysis of ternary nanofluid behavior in complex rotating and stretching disk geometries.