EXPERIMENTAL-ANALYSIS OF UNSTEADY FLOWS THROUGH A STENOSIS

In this paper we present a study of the post-stenotic velocity flow he ld corresponding to oscillatory, pulsatile and physiological flow wave forms. Two-dimensional velocity measurements are performed in a 75% se verity stenosis using a pulsed Doppler ultrasonic velocimeter. Emphasi s is placed on the analysis of the experimental velocity-profile patte rns. It is recognized that, beyond the influence of the how parameters such as the Reynolds number and the frequency parameter, velocity pro files (hence wall-shear stresses) highly depend on the flow waveform. In addition to this analysis, a model of the stenosis influence length is proposed in the case of oscillatory flow. (C) 1998 Elsevier Scienc e Ltd. All rights reserved.