Application of large-eddy simulation to the study of pulsatile flow in a modeled arterial stenosis

The technique of large-eddy simulation (LES) has been applied to the study, of pulsatile flow through a modeled arterial stenosis. A simple stenosis m odel has been used that consists of a one-sided 50 percent semicircular con striction in a planar channel. The inlet volume flux is varied sinusoidally In time in a manner similar to the laminar flow simulations of Tutty (1992 ). LES is used to compute flow at a peak Reynolds number of 2000 and a Stro uhal number of 0.024. At this Reynolds number, the flow downstream of the s tenosis transitions to turbulence and exhibits all the classic features of post-stenotic flow as described by Khalifa and Giddens (1981) and Lieber an d Giddens (1990). These include the periodic shedding of shear layer vortic es and transition to turbulence downstream of the stenosis. Computed freque ncy spectra indicate that the vortex shedding occurs at a distinct high fre quency, and the potential implication of this for noninvasive diagnosis of arterial stenoses is discussed. A variety of statistics have been also extr acted and a number of other physical features of the flow are described in order to demonstrate the usefulness of LES for the study of post-stenotic f lows.