Abstract

Particle Imaging Velocimetry and Laser Doppler Anemometry are often used in research into blood flow (haemodynamics). This paper shows how a largescale model of an arterial junction (a distal anastomosis, or bypass graft) can be used to represent the in vivo blood flow provided the correct scaling procedures are applied. Blood is a non-Newtonian liquid whose viscosity can be represented by a power law. Dimensional analysis shows that a pulsatile flow of a power-law fluid can be characterised by a generalised Reynolds number, the Strouhal number, the Pulsatility Index, and by the power-law exponent n. It is clearly demonstrated in this paper that a non-Newtonian liquid cannot be properly represented by a Newtonian liquid, but it can be very well represented by a non-Newtonian liquid that has the same power-law exponent. If, however, the common practice of using a Newtonian liquid is adopted, the wall shear stress along the bed of the anastomosis will be seriously over-predicted by as much as 100-200. © 2003 IOP Publishing Ltd.