Pulsatile Non- Newtonian Blood Flow Under The Influence Of A Transverse Magnetic Field: A Magnetohydrodynamic Study

Blood flow in human arteries is inherently pulsatile and exhibits non-Newtonian behavior, driven by the rhythmic cardiac cycle and influenced by shear-dependent viscosity arising from plasma and cellular interactions. This study investigates the magnetohydrodynamic (MHD) effects of a transverse magnetic field on pulsatile non-Newtonian blood flow, with particular emphasis on velocity distribution, wall shear stress (WSS), flow resistance, and hemodynamic responses in stenosed arteries. Blood is modeled as a Casson fluid, capturing shear-thinning and yield stress characteristics, while the transverse magnetic field generates a Lorentz force opposing flow. Governing momentum equations are formulated in cylindrical coordinates and solved using analytical techniques (Finite Hankel transforms) complemented by numerical simulations for pathological and pulsatile conditions. The analysis reveals that increasing the Hartmann number (Ha) significantly reduces centerline velocity, flattens velocity profiles, and decreases WSS, whereas higher Casson parameters (β) produce blunter, plug-like profiles with higher central velocity and lower boundary shear. Pulsatility, represented by the Womersley number (α), introduces phase-lagged oscillations, and stenosis severity amplifies local velocities and WSS, increasing flow resistance. Additionally, Joule heating due to induced currents modestly raises blood temperature, relevant for hyperthermia therapy. These findings have significant implications for MRI safety, magnetic drug targeting, and vascular disease management, providing quantitative insight into the interplay of magnetic fields, non-Newtonian rheology, and pulsatile hemodynamics in arteries.