Key result
Tortuous vessel geometry in computational models induces counter-rotating vortices and shifts peak velocity outward.
Why the study?
Geometric parameters affect hemodynamics, but the specific effect of vessel tortuosity in straight and bifurcating tubes under pulsatile flow conditions required further evaluation.
Computational modeling demonstrates that vessel tortuosity and bifurcation significantly alter hemodynamic profiles, including velocity distribution and vortex formation under pulsatile flow.
Pulsatile CFD reveals vortices and velocity shifts in tortuous vessels; leaves open translation to clinical risk assessment.
The present work is focused on the study of hemodynamic characteristics for tortuous arteries/veins in a pulsatile flow. This work is an extension of an earlier work by the author, which reported the hemodynamic characteristics in a steady flow situation. It is a well-known fact that various geometric parameters affect the hemodynamics, such as the diameter of vessels, the diameter of mother and daughter tubes in bifurcation, the angle between them, and their relative magnitudes. This paper is focused on the effect of tortuosity produced in straight and bifurcating tubes under pulsatile flow conditions. A heartbeat rate of 120 bpm is considered for pulsation, covering one cycle of systole and diastole. The measure of tortuosity is defined by the varying pitch and the amplitude. The present analysis is carried out computationally using ANSYS. Results are presented through secondary flow streamline, velocity profile, and its effect on wall shear stress. Key findings are that secondary vortices are observed in the bifurcated model and counter-rotating vortices are observed in the wavy tube geometry. The velocity distribution is asymmetric in the case of the plain bifurcation geometry. In the case of the wavy tube and bifurcated geometry, there is a shift in peak velocity from the inner to the outer wall, depending on the crest and trough positions of the tortuous vein. Relative change in magnitude of velocity for wavy tube depends on the depth and pitch of wavy wall of the tortuous tube. The velocity reduces with an increase in time step for unsteady flow.
No takes yet. Share an insight, caveat, or question.
Kotian et al. (2024) studied Tortuous arteries and veins. Wavy/tortuous geometry in straight and bifurcating tubes vs. Plain bifurcation geometry was evaluated on Hemodynamic characteristics (secondary flow streamline, velocity profile, wall shear stress). Computational modeling of tortuous arteries and veins under pulsatile flow demonstrated that wavy tube geometry induces counter-rotating vortices and shifts peak velocity from the inner to outer wall.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: