The finite volume method and CFD simulation of circle of Willis blood flow

In this seminar, we begin with a brief explanation of the significance of blood flow modelling to CoW aneurysms and an overview of the aspects of CFD blood flow modelling. We then proceed with an introduction to the latest finite volume method derivation and, following on, outline the addition of a pressure boundary condition. It represents a significant improvement with respect to the ability to manage the spatial discretization error. Wall shear stress results are shown from a two-dimensional, rigid CoW model, with pulsatile inlet pressure conditions and resistance outlet conditions. Three simulation set-ups cover a physiologically representative range of flows: symmetric inlet conditions and configuration; internal carotid artery inlet pressure phase difference and symmetric configuration; symmetric inlet conditions and a narrow proximal (A1) section of the left anterior cerebral artery. Following on from the two-dimensional CFD model, we show some results of a similar model in three dimensions which uses the ANSYS CFX solver. An evaluation of the accuracy of the three-dimensional model is shown along with some simulation results for the flow in the CoW and ACoA.