Atherosclerosis and disturbances in flow.
From experiments on flow in a tapered tube it was found that a ring vortex could be produced in certain circumstances. The parameter which determines the vortex formation is the product of peak reversed flow, Reynolds number, and the taper angle of the tube. Using dimensional analysis, conditions in a model were adjusted to simulate those in the unbranched superficial femoral artery. A vortex was formed when there was sufficiently strong reversed flow, and it did so over a range of nondimensional frequencies similar to those which occur in the artery in humans. When the vortex passes up the tube, the surface stresses oscillate at a frequency an order of magnitude higher than the pulse frequency. It is possible that this oscillating stress could trigger atherosclerosis. The initiating ring vortex could be induced by a slight stenosis distal to the site of atherogenesis.
Charlesworth
D
D
Department of Surgery, University of Manchester, United Kingdom.
Gerrard
J H
JH
D001161:Arteriosclerosis / Q000503:physiopathology*; D001783:Blood Flow Velocity; D005263:Femoral Artery / Q000503:physiopathology*; D006801:Humans; D008955:Models, Cardiovascular; D009716:Numerical Analysis, Computer-Assisted