Cerebral artery aneurysms often form in the circle of Willis, most frequently in the asterior communication artery. This artery forms a junction between two confluent arteries and two bifurcating arteries. In the present study, the flow field around the anterior communicating artery is simulated by two confluent tubes, two bifurcating tubes, and junctional region connecting to four tabes. The wall shear stress and the velocity profile around the anterior communicating artery in laminar steady flow were experimentally studied using an electrochemical method and a laser Doppler velocimeter, respectively. The flow around the junction is found to be very unstable and the wall shear stress to vary greatly around the apex.
