Published online by Cambridge University Press: 29 November 2010
Abdominal aortic aneurysms are a dilatation of the aorta, localizedpreferentially above the bifurcation of the iliac arteries, which increases intime. Understanding their localization and growth rate remain two open questionsthat can have either a biological or a physical origin. In order to identify therespective role of biological and physical processes, we address in this articlethese questions of the localization and growth using a simplified physicalexperiment in which water (blood) is pumped periodically (amplitudea, pulsation ω) in an elastic membrane (aorta) (lengthL, cross-section A0 and elasticwave speed c0) and study the deformation of thismembrane while decharging in a rigid tube (iliac artery; hydraulic lossK). We first show that this pulsed flow either leads to ahomogenous deformation or inhomogenous deformation depending on the value of thenon-dimensional parameterc02/(aLω2K).These different regimes can be related to the aneurysm locations. In the secondpart, we study the growth of aneurysms and show that they only develop above acritical flow rate which scales asA0c0/.