Title: Effect of micromagnetorotation on magnetohydrodynamic blood flows
Abstract:
This presentation concerns the investigation of micropolar magnetohydrodynamic (MHD) blood flows, with and without the effects of micromagnetorotation (MMR). MMR refers to the magnetic torque caused by the misalignment between the magnetization of magnetic particles in the fluid and the external magnetic field, which influences the internal rotation (microrotation) of these particles. Blood can be modeled as a micropolar fluid containing magnetic particles due to the magnetization of erythrocytes. In this context, various types of MHD micropolar blood flows—such as 2D plane Poiseuille blood flow, blood flow through a simple 3D artery, through 3D stenosis, and through a 2D aneurysm—are discussed with respect to the effect of MMR. Key flow features, including streamlines, vorticity, velocity, and microrotation, are analyzed under different conditions: degrees of stenosis and aneurysm, hematocrit levels, and magnetic field strengths. The numerical results were obtained using two newly developed transient OpenFOAM solvers: epotMicropolarFoam and epotMMRFoam. The findings indicate that micropolar effects become more pronounced as vessel size decreases. Furthermore, when MMR is neglected that is, when blood is modeled as a classical MHD micropolar fluid without magnetic particles the magnetic field has little influence on blood flow, regardless of its strength, due to the minimal impact of the Lorentz force. Conversely, MMR substantially alters blood flow, particularly at higher hematocrit levels, leading to reductions of up to 50% in velocity and vorticity, and up to 99.9% in microrotation. At the same time, vortices and disturbances in the flow are significantly dampened. These findings underscore the critical role of MMR previously overlooked in modifying flow behavior in arteries, and suggest that it should be taken into account in future MHD micropolar blood flow studies, both numerical and experimental.
