Comparative analysis of the silver-gold and copper-titanium dioxide hybrid nanoparticles impact on flow and heat transfer of the pulsatile blood in occluded cerebral artery.

Arterial stenosis, which is the progressive narrowing of the lumen of blood vessels, severely compromises perfusion and leads to complex hemodynamic alterations. Evolving to address this challenge, hybrid nanofluids have emerged as a truly transformative solution due to their superior thermal and fluid properties. The present study numerically investigates the flow and heat transfer phenomena of two hybrid nanofluids, namely Silver-Gold (Ag-Au) and Copper-Titanium dioxide (Cu-TiO2), in a bifurcated artery with 50% stenosis. A three-dimensional computational model based on the FEM was developed to simulate the pulsatile, Newtonian, and incompressible blood flow. The effects of nanoparticle volume fraction, pulsation rate, and the stenosis geometry were systematically investigated on temperature distribution, velocity profiles, wall shear stress, and heat flux. It was observed that increasing the volume fraction of nanoparticles heightens thermal conductivity and, thus, heat transfer efficiency. For instance, at a volume fraction of 0.1, the hybrid Silver-Gold nanofluid achieved the highest ANN of 24.188 in comparison with the Cu- TiO2 at 20.456. The interaction of pulsatile flow with nanoparticles further augmented heat flux via periodic thinning of the thermal boundary layer, hence fostering flatter temperature profiles. Even though both hybrid nanofluids had comparable wall shear stress values of ∼1.426 N/cm2, Silver-Gold nanoparticles manifested better thermal efficiency and uniform temperature distribution. These results indicate that the hybrid nanofluids, especially Silver-Gold, may have enormous potential in biomedical applications like hyperthermia treatment, drug delivery, and vascular heat management. This study bridges critical gaps in understanding hybrid nanofluid dynamics in stenosed arteries, providing a foundation for future innovations in biomedical heat transfer and fluid mechanics.