A numerical study on steady flow in helically sinuous vascular prostheses.

The objective of the present study is to investigate flows in helically sinuous tubes with a small amplitude of helicity for physiological and clinical applications. Three-dimensional computations of steady flows in helically sinuous tubes are carried out by using a Navier-Stokes solver based on the spectral/hp element method for high accuracy. Results show that the flow fields are affected by the curvature and the torsion of the helically sinuous tube geometry in terms of axial velocity, axial vorticity and wall shear stress. The position of the maximum axial velocity is influenced more by the curvature than by the torsion. Most importantly, the torsion remarkably changes the Dean vortices produced by the curvature to a predominantly single vortex. Accordingly, it is proposed that the fluid dynamics knowledge gained from the present investigation can be utilized for the design of innovative prosthetic grafts that can control the biological reactivity of coagulant interacting with the prosthetic vascular surface or wall.