Visualization and finite element analysis of pulsatile flow in models of the abdominal aortic aneurysm.

摘要: Pulsatile flows in glass models simulating fusiform and lateral saccular aneurysms were investigated by a flow visualization method. When resting fluid starts to flow, the initial motion is practically irrotational. After short period of time, began separate from proximal wall aneurysm. Then separation bubble or vortex grew rapidly size filled whole area aneurysm circumferentially. During this center moved end distal point The transient reversal for instance, which may occur at ejection period, passed between centrally located vortex. rate pulsatile frequency high, broke down into highly disturbed (or turbulence) portion same effect was observed when length increased. A reduction amplitude made pattern close that steady flow. finite element analysis obtain velocity pressure fields through tube with an axisymmetric expansion. Calculations performed used experiment order study effects change wave form keeping time-mean Reynolds number Womersley's parameter unchanged. Calculated instantaneous patterns field stream lines agreed well experimental results. appearance disappearance dilated its development resulted complex distributions shear fields. Locally minimum maximum values stress occurred points just upstream downstream expansion reached peak.