Analysis of magnetohydrodynamic micropolar blood flow and nanoparticles magnetic targeting in blood vessels

Purpose This paper aims to numerically solve the transient magnetohydrodynamic pulsatile two-dimensional (2D) flow of micropolar blood with heat and mass transfer through the injection of magnetic nanoparticles (MNPs) that are transported inside the blood vessel and captured in the stenosis by the action of an external magnetic field, based on the nanofluids transport model of Buongiorno (which takes into account the Brownian and thermophoretic mechanisms) and micropolar fluids transport model of Eringen (which considers the microrotational movements of blood cells). Design/methodology/approach A transient 2D transport model for blood flow with heat and mass transfer was developed based on the laws of conservation of linear momentum, angular momentum, energy and mass in their dimensionless form. The problem was then solved by means of an analytical approach, a numerical solution applied directly to the original model (2D transient model) and a numerical solution with spatial discretization of the radial direction through the method of lines (one-dimensional transient model) and then computationally implemented using the NDSolve subroutine of the numerical-symbolic computing platform Mathematica 13.0. Findings The velocity field slightly decreases in the stenosis region due to magnetic effects and reduced microrotation. Temperature rises locally from Joule heating. Fraction of nanoparticles (NPs) increases near the stenosis as reduced velocity enhances diffusion over convection. High NP concentrations appear near the injection site. Along the stenosis, NPs accumulate at the wall due to magnetic attraction. NP transport is primarily radial, from the center toward the wall. Streamlines converge in the stenosis, confirming accumulation. Magnetic field intensity and mean velocity have minimal influence. Higher NP death rates reduce NP presence, while low death rates allow pulsatile flow to enhance NP retention. Originality/value This study is highly important because of modeling blood as a micropolar fluid in which blood cells have their own rotational movement, using the Eringen micropolar fluid model (1966); modeling blood flow through injection, mass transfer and capture of MNPs by the action of the magnetic field in the stenosis region; considering the effects of thermophoresis and Brownian motion for blood flow with MNPs through the application of the Buongiorno nanofluid transport model (2006); and admitting the existence of a kinetic process of MNP death related to drug delivery to the target tissue.