Flow oscillations as a natural factor of reduction of the effect of RBC aggregation on blood flow

Abstract

One of the mechanical factors affecting significantly RBC aggregation, and consequently blood flow, is the oscillatory character of flow. This fact follows from the measurement of RBC aggregation and rheological behaviour of blood in both steady shearing flow and steady shearing flow with superposed oscillations. At the comparable flow conditions, RBC are more disaggregated in oscillatory flow due to oscillations then in steady shearing flow. Consequently, the viscous character of blood rheological behaviour in oscillatory flow does not change so significantly with decreasing intensity of flow as shear viscosity and the effect of elasticity on blood flow is nearly eliminated. It suggests that the significance of various changes in RBC aggregability of different origin may be substantially suppressed in oscillatory flow of blood in spite of the decisive effect of the aggregability changes on blood shear viscosity and steady shearing flow.