Effect of Stenosis Severity on the Hemodynamics of an Idealized Straight Arterial Tube

The present study examines the effect of stenosis severity on arterial hemodynamics using the immersed boundary method-based in-house numerical code. A realistic physiological velocity waveform varying in time and parabolic in space is adopted as an inlet boundary condition in a straight arterial tube with single asymmetric stenosis. The flow is considered to be laminar and incompressible, assuming blood as a Newtonian fluid. The degree of stenosis (DS) is defined by the obstructed cross-sectional area. The velocity and vorticity contours demonstrate that increment in DS results in further disturbances in the flow downstream of the stenosis. The areas with low Time-Averaged Wall Shear Stress (TAWSS) and high Oscillatory Shear Index (OSI) are more prone to further plaque deposition, and areas with high TAWSS, such as throat of the stenosis, are potential sites for thrombus formation. The magnitude of the peaks in the cyclic pressure drop across the stenosis rises with its severity. However, in the present study, a greater pressure drop is noted at 45% stenosis (DS45) case as compared to 65% stenosis (DS65) case as some pressure recovery occurs in the latter case.