Wall vibrations induced by flow through simulated stenosis in models and arteries.

Abstract The paper describes a series of model and in vivo experiments in which vessel-wall vibrations. due to flow through simulated arterial stenoses, are investigated. The model studies utilize various axisymmetric constrictions inserted into two different flexible tubes. The flow through the models is steady, with the Reynolds numbers Re, ranging from 400 to 5000. Wall vibration intensity, I, a measure of the wall vibration amplitude, is found to be described by: I = K( D d ) 4 (Re) 2.2 where the coefficient K is dependent in part upon tube wall properties, D is the unobstructed vessel diameter, and d is the lumen diameter of the stenosis. Frequency spectra of wall vibrations and the axial position of maximum vibration intensity are also described. The in vivo studies utilize similar constrictions inserted into canine femoral arteries, and a qualitatively similar relation between wall-vibration intensity and fluid-dynamic parameters was observed. The results of this study correlate closely with the hydrodynamics of a separated, axisymmetric, bounded jet.