Abstract
The mechanics of branching blood flow is of fundamental importance in understanding the nonuniform distribution of blood components within a microvascular network and, indeed, even within an individual vessel. The nonuniformity resulting from the branch can in turn impact microvascular flow impedance and oxygen transport processes. A construct known as the “separation surface” is often used to describe the flow at converging (venular) and diverging (arteriolar) branches. In the case of two converging flows, the separation surface identifies the portions of the flow in the outlet branch which originated from each of the two feeding branches. The reverse situation holds for a diverging branch. If the converging fluids are immiscible, then the separation surface is a persistent, physical surface within the flow. For converging blood flow, mixing occurs and the separation surface loses its definition with downstream position.