Significance of Thermal Radiation in Heat Transfer of MHD Blood Based CNTs Hybrid Nanofluids Past a Stretching/Shrinking Sheet: A Couple-Stress Fluid Model

The effect of thermal radiation on heat transport in a steady, two-dimensional blood-based nanofluid is studied. Blood is the base fluid with Multiwalled Carbon Nanotubes (MWCNT) and Single-Walled Carbon Nanotubes (SWCNT) nanoparticles. Blood flow is described with the couple-stress fluid model. Thermal radiation, couple stress effects, and viscous dissipation effects are considered, and the governing partial differential equations are transformed with similarity transformations, resulting in nonlinear ordinary differential equations, which are solved analytically with the Homotopy Analysis Method (HAM). The results investigated the velocity and temperature profiles, as well as the skin-friction and Nusselt-number distributions, across the shrinking/stretching sheet. The thermal radiation parameter was found to improve the Nusselt number by about 15%, improving the heat transfer rate. The couple stress parameters were found to reduce skin friction and strengthen the boundary layer. The heat transfer rate increased with a higher nanoparticle volume fraction, and SWCNTs resulted in a 42% increase in the Nusselt number compared to the blood-based fluid. The results are valuable in biomedical applications, especially in hyperthermia-based thermal therapy and drug delivery systems, in devices with high thermal regulation, such as artificial hearts and hemodialysis, and in thermal regulation devices.