Steady hydromagnetic and entropy analysis of Casson tri-hybrid nanofluid flow in a porous medium incorporating hall and triple radiation effects

This study investigates the magnetohydrodynamic flow and heat transfer of a Casson tri-hybrid nanofluid (blood-based) over a rotating porous surface, incorporating Hall current, viscous dissipation, and thermal radiation. Unlike previous works, this research uniquely integrates tri-hybrid nanoparticles (TiO 2 , Fe 3 O 4 , Au) in a Casson blood fluid, Hall current and porous rotation effects, and a comparative analysis of linear, nonlinear, and quadratic thermal radiation models within a single framework. The governing equations are solved numerically using the MATLAB bvp4c method. The analysis is carried out over the following parametric ranges: Eckert number (0.01 ≤ \(Ec*\) ≤ 0.05), porosity parameter (0.01 ≤ \(β*\) ≤ 0.3), and Hall current parameter (0.1 ≤ \(m*\) ≤ 03). Key outcomes show that magnetic field, Hall current, and porosity reduce radial and azimuthal velocities but increase temperature and entropy generation. Viscous dissipation and Joule heating significantly elevate the thermal field. The Bejan number decreases with higher Casson and porosity parameters, indicating the dominance of frictional irreversibility. Nonlinear radiation produces the highest entropy generation and heat transfer enhancement, followed by quadratic and linear models. Skin friction and Nusselt numbers are highly sensitive to the choice of radiation model. These findings offer critical insights for biomedical thermal therapies, magnetically guided drug delivery, rotating cooling systems, and advanced energy applications requiring electromagnetic and thermal regulation.