Affiliations: [a] Faculty of Engineering, Kansai University, Suita, Osaka, Japan | [b] Department of Bioengineering, University of California, San Diego, LaJolla, CA, USA
Abstract: To study the rheological behavior of blood cells in various flow patterns through narrow vessels, we analyzed numerically the motion of blood cells arranged in one row or two rows in tube flow, at low Reynolds numbers. The particles are assumed to be identical rigid spheres placed periodically along the vessel axis at off-axis positions with equal spacings. The flow field of the suspending fluid in a circular cylindrical tube is analyzed by a finite element method applied to the Stokes equations, and the motion of each particle is simultaneously determined by a force-free and torque-free condition. In both cases of single- and two-me arrangements of the particles, their longitudinal and angular velocities are largely affected by the radial position and the axial spacing between neighboring particles. The apparent viscosity of the asymmetric flows is higher than that of the symmetric flow where particles are located on the tube centerline, and this is more pronounced when particles are placed farther from the tube centerline and when the axial distance between neighboring particles is reduced.
Keywords: Red cells, Stokes flow, two-me flow, apparent viscosity
DOI: 10.3233/BIR-1997-34303
Journal: Biorheology, vol. 34, no. 3, pp. 155-169, 1997
