THE FINITE ELEMENT ANALYSIS OF PULSATILE FLOW PATTERNS ASSOCIATED WITH AN ARTERIAL STENOSIS
动脉局部狭窄时脉动流的有限元分析

Pulsatile flow patterns in rigid arterial models with stenosis (area constrictions) of 50% and 80% have been studied using the Finite Element Methods. Flow patterns of the constricted region have been investigated for a simulated physiological condition with an average Reynolds number of 561.8 and a Womersley number of 7.16. Velocity waveforms, axial pressure drop and wall shear stress distributions have been computed for each model and presented at several time steps. Flow separation zone near the stenosis was also studied. Results have been validated by comparing the recordings of Doppler velocimeter obtained in the in vitro experiments by the authers, and by other experimental work reported in the literature.Results showed thai due to the stenosis,1) the peak values of velocity, pressure drop arid wall shear stress increase; 2) waveforms of these three variables broaden and phase differences appear; 3) flow separations occur. It is noted that among the three variables, the wall shear stress is the most sensible indicator to the degree of stenosis. Results also showed that 4)-pulsatile flow separation occurs at both sides of the stenosis in an"off and on" manner; and 5) the maximum wall shear stress of flow in 80% stenotic model is very close to the value of 40 Pa qucted to cause a cute endothelial disruption (Fry, 1968).