THE INFLUENCE OF WALL COMPLIANCE ON FLOW PATTERN IN A CURVED ARTERY EXPOSED TO A DYNAMIC PHYSIOLOGICAL ENVIRONMENT: AN ELASTIC WALL MODEL VERSUS A RIGID WALL MODEL

Abstract

Plenty of well-established medical research works have shown that many vascular diseases such as stenosis and atherosclerosis are prone to appear in curved arteries. In this paper, we investigated the influence of wall compliance on flow pattern in curved arteries exposed to dynamic physiological environments in order to understand the hemodynamic mechanism and provide a basis for clinical research in related areas. Representative curved arteries with elastic and rigid walls are constructed by computers. The fluid-structure interaction (FSI) effect is considered in our calculations. Physiological velocity profile is assigned as the inlet boundary condition. No-slip boundary condition is applied at the blood-wall interface. Our results show that the maximum axial velocity in the rigid wall model is larger than that in the elastic wall model. Wall compliance also has a remarkable effect on backflow patterns. Significant differences in pressure distribution are found between the elastic and rigid wall models. Blood strain rate distribution patterns in the two models were also compared. It was interesting to discover that in the straight part of the artery, the flexible wall made the counter-rotating vortices induced by the curvature gradually disappear along a downstream direction. However, for the flow feature in the rigid wall model, strong vortices existed throughout the entire straight part of the artery. It revealed that the increment of wall rigidity results in a reduction in wall movement capacity, thus affecting the physiological function of the arterial wall, making it incapable of effectively regulating the flow pattern inside the artery. The current work indicates that the influence of wall compliance on flow pattern in curved artery is significant.