A mathematical model of the flow in the axial plasmatic gaps of the smaller vessels

The flow in the axial plasmatic gaps of the smaller vessels of the microcirculation has been studied by numerical solution of the creeping flow equations in a simplified model of the capillaries. Stream functions, velocity distributions, pressure drops and circulation times have been obtained for t hree axisymmetric configurations: erythrocytes spanning the entire lumen, with erythrocyte-plasma interface straight (Model A) and curved (Model B) and erythrocytes spanning only a portion of the lumen, with straight interface (Model C). The results for Model A have also been compared with those for the corresponding two-dimensional case. The most important finding is that the circulation pattern in the spaces between erythrocytes is of primary importance in determining the pressure drop, but can have only limited influence on the oxygen and heat transfer processes in a capillary.