Non-Newtonian flow of blood in arterioles: consequences for wall shear stress measurements.
OBJECTIVE
Our primary goal is to investigate the effects of non-Newtonian blood properties on wall shear stress in microvessels. The secondary goal is to derive a correction factor for the Poiseuille-law-based indirect measurements of wall shear stress.


METHODS
The flow is assumed to exhibit two distinct, immiscible and homogeneous fluid layers: an inner region densely packed with RBCs, and an outer cell-free layer whose thickness depends on discharge hematocrit. The cell-free layer is assumed to be Newtonian, while rheology of the RBC-rich core is modeled using the Quemada constitutive law.


RESULTS
Our model provides a realistic description of experimentally observed blood velocity profiles, tube hematocrit, core hematocrit, and apparent viscosity over a wide range of vessel radii and discharge hematocrits.


CONCLUSIONS
Our analysis reveals the importance of incorporating this complex blood rheology into estimates of WSS in microvessels. The latter is accomplished by specifying a correction factor, which accounts for the deviation of blood flow from the Poiseuille law.
Department of Mechanical and Aerospace Engineering, University of California, San Diego, California, USA.
Krishna
K
Sriram
Marcos
M
Intaglietta
Daniel M
DM
Tartakovsky
D000465:Algorithms; D001160:Arterioles / Q000502:physiology*; D001783:Blood Flow Velocity; D001809:Blood Viscosity; D003198:Computer Simulation; D004912:Erythrocytes / Q000502:physiology; D006400:Hematocrit; D018056:Hemorheology; D008955:Models, Cardiovascular; D013314:Stress, Mechanical
apparent viscosity; blood rheology; hematocrit; plasma layer; shear stress; shear thinning