Numerical Study on Three-Dimensional Unsteady Blood Flow through an Artery with a Small Side Branch.

Three-dimensional unsteady blood flow through an artery with a small side branch was numerically analyzed using the finite-element method. Our main focus was on the model in which the angle between the trunk and the small side branch was larger than 90 deg. This arterial geometry is generally observed in a real arterial system. For this study, the arterial wall was assumed to be rigid and the non-Newtonian effect of blood was not taken into consideration. The calculation results are summarized as follows. 1) The branch angle does not have a strong effect on the flow rate through the side branch. 2) In the case of a large branch angle, the still-standing stagnation point appears near the outer wall of the small side branch. Moreover, this still-standing stagnation point has an effect of increasing the values of wall shear stress gradient (WSSG).