Toward a Constitutive Equation for Blood.

摘要

Closure of the conservation equations of fluid mechanics requires a constitutive equation. Viscometric measurements are not sufficient to uniquely determine such an equation. This study was undertaken to determine a constitutive equation for blood by the comparison of theoretical and experimental results for the problem of the stability of circular Couette flow. Based on the literature, a four constant Oldroyd model equation was chosen as a constitutive candidate for blood. Theoretical examination of the model in simple flow situations showed that it was capable of qualitatively predicting many of the observed characteristics of blood. Comparison of theory and experiment showed that the Oldroyd model was insufficient to characterize the rheological behavior of blood. The failure of the equation was most likely due to the oversimplicity of the linear model from which it was derived.