Pulsatile pressure and flow in an arterial aneurysm simulated in a mathematical model.

The pressure and flow patterns within arterial aneurysms are little known. In the present work the equations describing pulsatile flow, the Navier-Stokes equations, are solved numerically using the finite element method with a computer. The solutions of the Navier-Stokes equations are obtained at 24 points in time during the cardiac cycle. At selected instants in time, the solutions are presented as velocity vectors, streamlines and isobars. The results demonstrate a vortex formation during most of the cycle. The pressure within the aneurysm is nearly constant. At the downstream end of the expansion, high pressure gradients are found.