@article{Cookson:2008:10.1007/s10439-009-9636-y,
author = {Cookson, AN and Doorly, DJ and Sherwin, SJ},
doi = {10.1007/s10439-009-9636-y},
journal = {Ann. Biomed. Engrg.},
pages = {710--721},
title = {Mixing through stirring of steady flow in small amplitude helical pipes},
url = {http://dx.doi.org/10.1007/s10439-009-9636-y},
volume = {37},
year = {2008}
}

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TY  - JOUR
AB  - In this paper we numerically simulate flow in a helical tube for physiological conditions using a co-ordinate mapping of the Navier–Stokes equations. Helical geometries have been proposed for use as bypass grafts, arterial stents and as an idealized model for the out-of-plane curvature of arteries. Small amplitude helical tubes are also currently being investigated for possible application as A–V shunts, where preliminary in vivo tests suggest a possibly lower risk of thrombotic occlusion. In-plane mixing induced by the geometry is hypothesized to be an important mechanism. In this work, we focus mainly on a Reynolds number of 250 and investigate both the flow structure and the in-plane mixing in helical geometries with fixed pitch of 6 tube diameters (D), and centerline helical radius ranging from 0.1D to 0.5D. High-order particle tracking, and an information entropy measure is used to analyze the in-plane mixing. A combination of translational and rotational reference frames are shown to explain the apparent discrepancy between flow field and particle trajectories, whereby particle paths display a pattern characteristic of a double vortex, though the flow field reveals only a single dominant vortex. A radius of 0.25D is found to provide the best trade-off between mixing and pressure loss, with little increase in mixing above R = 0.25D, whereas pressure continues to increase linearly.
AU  - Cookson,AN
AU  - Doorly,DJ
AU  - Sherwin,SJ
DO  - 10.1007/s10439-009-9636-y
EP  - 721
PY  - 2008///
SP  - 710
TI  - Mixing through stirring of steady flow in small amplitude helical pipes
T2  - Ann. Biomed. Engrg.
UR  - http://dx.doi.org/10.1007/s10439-009-9636-y
UR  - http://www2.imperial.ac.uk/ssherw/spectralhp/papers/ABME_CoDoSh08.pdf
UR  - http://www.springerlink.com/content/r340x66078g7v108/?p=6459772e890744a6afa396593ef00629&pi=6
UR  - http://hdl.handle.net/10044/1/1472
VL  - 37
ER  - 

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