ABSTRACT
Knowledge of the fluid flow within the cardiovascular system is important for the understanding of atherosclerosis, a disease of the medium to large arteries involving the build-up of fatty deposits, and the biggest killer in the western world. Arteries are typically 4-6 mm in diameter, and are complex in their construction, shape and behaviour. In recent years LDA and PIV techniques have been applied to this field of research in an attempt to understand the detailed nature of the flow. Since it is extremely difficult to make detailed flow measurements in vivo, physical models that accurately represent the flow conditions in the cardiovascular system are needed. The great majority of measurements are made in life-scale geometries in the belief that this is the best way to reproduce the correct flow conditions. Also, blood is known to be a non-Newtonian liquid, but the majority of studies employ Newtonian liquids in the belief that the non-Newtonian behaviour does not have an important effect. A major weakness of working with small-scale models is that it makes it more difficult to obtain good resolution in the measurements. An engineering approach to this problem would be simply to increase the size of the model, identify the appropriate dimensionless groups, and apply the necessary scaling procedures . This approach does not appear to have been adopted in mainstream haemodynamics research.
