We conducted blood flow analysis, using the Fluid-Structure Interaction (FSI) method, to examine how changes in the material properties of blood vessels affect blood flow characteristics, using the carotid artery as the model vessel. The geometry of the blood vessel included 50% stenosis at the center, and blood was modeled as a non-Newtonian fluid. In order to investigate the effects of vessel material properties, linear elastic models with 0.21 MPa, 0.51 MPa, and 1.25 MPa, which are within the typical elastic modulus range of the carotid artery, were used to simulate the blood vessel, and these were compared with the rigid body model. The difference in blood vessel elasticity caused periodic and transient changes in blood flow. The more elastic the blood vessel becomes, the longer the periods of velocity, pressure, and Wall Shear Stress (WSS) change and the smaller the size of the Fluid Recirculation Zone (FRZ). Also, transient changes in blood flow occurred due to the accumulation of differences in flow caused by vessel wall deformation. This is because a change in the stiffness of the vessel wall causes the vessel's vibration period to change, leading to changes in blood flow.
In the present study, a high Reynolds number version of a turbulence model was proposed by using drag reduction to analyze the turbulent flows of power-law fluid for engineering applications. In order to determine the model constants in the constitutive equation, numerical simulation was conducted under the same conditions that were applied to obtain the experiment results and previous turbulence models. For validation of the modified turbulence model, numerical simulations were performed for power-law fluids of different viscosities. The results of the modified k- turbulence model showed better agreement with the experimental results than those of the standard k- turbulence model. In addition, computation time and computer resource of the modified k- turbulence model were reduced by about one third as compared to the low Reynolds number model for power-law fluids. power-law fluid, turbulent flow, drag reduction, turbulence model, computational fluid dynamics (CFD) Citation: Ro K, Ryou H S. Development of the modified k- turbulence model of power-law fluid for engineering applications.
Most of aneurysms in the cranial cavity occur at the bifurcation of anterior circulation system. A cerebral aneurysm is easily ruptured, and it is fatal for most patients. Generally it is known that aneurysm occurs when arterial wall is deformed by high pressure or high wall shear stress (WSS). A blood flow pattern and the geometry and the blood vessel are important factors for aneurysm formation and the location. The transient interaction between blood flow and the arterial wall affects for simulating deformation of the blood vessel. Thus, numerical analysis is performed for various bifurcation angles and flow rate ratio in bifurcation artery with different diameters to predict the location of aneurysm by hemodynamic characteristics of blood flow. A bifurcation angle between the internal carotid artery and the anterior cerebral artery (ACA) increased, a region of high pressure moved to the bifurcated artery with larger bifurcation angle when ratio of blood flow rate is constant case. When the ratio of blood flow increased, the region of high wall shear stress moved to the side of large flow rate ratio. Our results showed that the high WSS or high pressure region occur at the location of aneurysm as mentioned in the clinical research. Thus, this indicates that the geometry of blood vessel and blood flow rate affect the location of the anterior circulation aneurysm.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.