Flow into an Arterial Branch Model

Arterial branches are found to be a major site for formation of arterial plaque. In this study, several of the main parameters that influence the local flow into an arterial branch model are investigated. In particular, the role of the local geometric parameters of the bifurcation on the overall flow is thought to be interesting. How the changes in the bifurcation geometry influence the distribution of axial wall shear and pressure in the model, is investigated. The major geometric factors influencing this flow are the bifurcation area ratio and angle. The flow in a large number of geometric variations of the branch model is numerically simulated. The models at several branch area ratios in the range of 0·4≤ AR≤ 2·0 are considered. In the above range of area ratios, a range of branch opening half-angle of is also studied. The flow in the above models is calculated for the inlet-flow Reynolds numbers of 250, 500, 1000, and 2000. The asymmetric mass flow into the branches by imposing different exit pressures at the branch outlets is also investigated. Area ratio seems to have the largest influence on the flow within the physiologically relevant range of the parameters considered. Increasing the area ratio can lead to relatively large flow separation in the vicinity of the bifurcation region. At higher values of the opening angle of the bifurcation, the possibility and severity of flow separation at the appropriate wall location increases. Having asymmetric mass flow into different branches also increases the chance of separation at the opening of the constricted branch. The relative influence of the convective acceleration of the flow, as represented by the value of the flow Reynolds number, is also investigated. The particular value of the area ratio or bifurcation angle, necessary to initiate flow separation, is influenced by the Reynolds number of the incoming flow in the mother tube. In particular, the influence of all these parameters on flow properties and their relative importance is quantified. The relation between the influence of these parameters on the flow and the formation of some vascular diseases reported in the literature, is also examined.