UNSTEADY-FLOW OF CASSON FLUIDS THROUGH THE ECCENTRIC CIRCULAR TUBE

As a model of the flow through the false lumen of the dissecting aortic aneurysm, the starting and stopping flows of the Casson fluid through the eccentric circular tube are studied numerically. The calculations are performed by using the one-direction fully developed unsteady flow model. The calculation results show that the non-Newtonian property of the Casson fluid has the following two effects. One is the decrease in the flow rate through the false lumen. the other is the effect to strengthen the non-uniformity of the velocity distribution in the false lumen. Moreover. the calculations based on a triphasic waveform measured by McDonald are performed and the development of the dissecting aortic aneurysm is discussed on the basis of the calculated wall shear stress.