Effect of Secondary Curvature on Mixing Characteristic within Constant Circular Tubes

In this study, numerical simulations on laminar flow in sinusoidal wavy shaped tubes were conducted for mean Reynolds number of 250, which is in the range of physiological flow-rate and investigated flow structures, pressure distribution and particle trajectories both in steady and periodic inflow conditions. For extensive comparisons, various wave lengths and amplitudes of sine function for geometry of tube models were employed. The results showed that small amplitude secondary curvature has significant influence on the nature of flow patterns and particle mixing mechanism. This implies that characterizing accurate geometry is essential in accurate predicting of in vivo hemodynamics and may motivate further study on any possibility of reflection of secondary flow on vascular remodeling and pathophysiology.

Authors:

• Minh Tuan Nguyen
• Sang-Wook Lee

Keywords:

• Secondary curvature
• Sinusoidal wavy tubes
• Mixing Characteristics
• Pulsatile flow
• Hemodynamics.

References:

[1] M. Ford, Y. Xie, B. Wasserman, and D. Steinman, "Is flow in the
common carotid artery fully developed?" Physiol. Meas., Vol. 29, 2008,
pp. 1335-1349.
[2] J. Myers, J. Moore, M. Ojha, K. Johnston, and C. Ethier, "Factors
influencing blood flow patterns in the human right coronary artery," Ann.
Biomed. Eng., Vol. 29, 2001, pp. 109-120.
[3] A.N. Cookson, D.J. Doorly, and S. J. Sherwin, "Mixing through stirring
of steady flow in small amplitude helical tubes," Ann. Biomed. Eng., Vol.
37, 2009, pp. 710-721.
[4] S.-W. Lee, L. Antiga, J.D. Spence, D.A. Steinman, Geometry of the
carotid bifurcation predicts its exposure to disturbed flow," Stroke, Vol.
39, 2008, pp. 2341-2347.
[5] C. Ethier, S. Prakash, D. Steinman, R. Leask, G. Couch, and M. Ojha,
"Steady flow separation pat-terns in a 45 degree junction," Journal of
Fluid Mechanics 411, 2000, 1-38.
[6] C. Ethier, D. Steinman, and M. Ojha, "Comparisons between
computational hemodynamics, photochromic dye flow visualization and
magnetic resonance velocimetry. In: Xu, X.Y., Collins, M.W.E. (Eds.),
The hemodynamics of arterial organs: comparison of computational
predictions with in vivo and in vitro data," WIT Press, 1999, pp. 131-183.
[7] A. Wake, "Modeling fluid mechanics in individual human carotid
arteries," PhD thesis, Georgia Institute of Technology, 2005.