Entropy generation analysis of EMHD blood flow conveying TiO2-Au nanoparticles in a time-dependent stenosis artery with hematocrit-dependent viscosity

Abstract

Purpose This study aims to numerically investigate the unsteady blood flow through an inclined, overlapping, time-variant stenosed artery under the influence of uniform magnetic and electric fields. A Casson fluid model is used to account for non-Newtonian hemorheological behavior, with blood viscosity modeled as hematocrit-dependent. The second law of thermodynamics is applied to evaluate entropy generation and flow irreversibility in the presence of nanoparticles. Design/methodology/approach The governing equations for non-Newtonian, electromagnetohydrodynamic blood flow are solved using an explicit finite difference scheme (FTCS). Hemodynamic parameters, such as velocity, temperature, entropy generation and Bejan number, are computed across varying hematocrit levels and nanoparticle types (Au and TiO2). Findings The results indicate that hematocrit and temperature difference are the most influential dimensionless parameters affecting entropy generation. Au/blood nanofluids exhibit consistently higher velocity and temperature profiles compared to TiO2/blood nanofluids. Regions of high entropy correspond to zones of intense shear and thermal gradients. The applied electric field enhances flow via electro-osmotic effects, while increasing hematocrit leads to higher flow resistance and energy dissipation. Originality/value Unlike prior studies that assume constant blood viscosity, this work incorporates hematocrit-dependent viscosity and evaluates the combined effects of magnetic and electric fields on entropy generation. The results offer deeper insight into thermodynamic efficiency in stenosed arteries and can inform biomedical applications in targeted drug delivery, blood purification and vascular device design.