Two-phase blood flow modeling and mass transport in the human aorta

In the present study we investigate the effects of both two-phase blood flow behavior and the pulsation of blood flow on the distributions of luminal surface of low density lipoproteins (LDL) concentration and oxygen flux along the wall of the human aorta. We compare the predictions of a two-phase model with those of the single phase one under both steady flow and realistic pulsatile flow conditions using a human aorta model constructed from CT images. As it has been noted, mass transfer of low-density lipoproteins (LDLs) may occur in the arterial system and is likely involved in the localization of atherogenesis. We utilized a tapered kind of the aorta in order to stabilize the flow of blood, thus delay the attenuation of the helical flow, making it move beyond the arch and into the first part of the descending aorta. The results therefore may be used to explain why the ascending aorta and the arch are relatively free of atherosclerosis. The dependence of viscosity and diffusivity on the local density is incorporated in the two-phase flow model rendering these quantities position dependent. For oxygen transport, we have compared the numerical results obtained with those utilizing the shear thinning non-Newtonian nature of blood. Finally, we examine the effect of pulsatile flow on the transport of LDLs and on the oxygen flux in the aorta.