Entropy generation in radiative MHD SWCNTs–MWCNTs–Fe3O4/water tri-hybrid nanofluid flow over a stretching porous surface with Joule heating

The present study investigates irreversibility analysis and thermal transport features in the radiation magnetohydrodynamic (MHD) flow of a SWCNTs–MWCNTs–Fe 3 O 4 /water tri-hybrid nanofluid over a permeable stretching porous surface in the existence of chemical reaction, Joule heating, viscous dissipative, and suction/injection effects. The application of a steady transverse magnetic field in the orientation normal to the stretching surface is ensured; on the other hand, thermal radiation and porous medium effects are accounted for in the mathematical model. The boundary value problem that results is numerically addressed by the MATLAB function bvp4c. Detailed analysis of the influences of appropriate physical parameters on velocity, temperature, concentration, entropy generation, and Bejan number distributions is conducted. According to the numerical outcomes, raising the magnetic parameter and porous medium parameter results in the diminishing of the fluid velocity due to the increasing Lorentz and drag forces, which causes the momentum boundary layer to become thinner. Besides, entropy generation enhances with the increase of magnetic field strength, Joule heating, viscous dissipation, and porous medium resistance, while the Bejan number suggests that under the specific ranges of the parameters, heat transmission irreversibility dominates over fluid friction irreversibility. Adding carbon nanotubes and magnetic nanoparticles results in a measurable upgrade of the thermophysical attributes of the base fluid, which in turn renders tri-hybrid nanofluids very promising for the progress of thermal management systems, energy devices, microelectronics, and biomedicine.