CFD modeling of multiphase blood flow under body acceleration

A CFD modeling investigation of the two-phase, non-Newtonian pulsatile blood flow for two realistic coronary arteries under body acceleration is presented in this thesis. The proposed CFD model is developed by using Ansys FLUENT v17 program. The unsteady pulsatile pressure profile, drag model, viscosity, and periodic body acceleration are implemented into CFD code by means of the user define functions (UDF) in the present investigation. An Eulerian-Eulerian two-fluid approach has been adopted to simulate the effect of body acceleration and describe flow behavior of each phase inside a human coronary artery. Blood is accepted two-phase; one phase is plasma, and the other is red blood cell. The modeling and analysis of the effect of acceleration are realized for two different arteries. Firstly, the effect of periodic body acceleration in a right coronary artery (RCA) is investigated. The main goal is to obtain the impact of acceleration on the hemodynamics factors of two-phase non-Newtonian blood flow such as wall shear stress, volume fraction, strain rate, and viscosity of the red blood cell (RBC) for the maximum and minimum curvatures of the realistic RCA. Then, the blood flow through the realistic left coronary artery (LCA) is investigated. The objective is to investigate the effect of the periodic body acceleration on the same hemodynamics parameters with the RCA for the bifurcation regions of LCA. Generally, the CFD simulation results for both RCA and LCA case studies indicated that periodic body acceleration plays a significant role on the hemodynamic parameters. By increasing amplitude of acceleration, the wall shear stress (WSS) increased in the inner side of the curvatures having the obtuse angle and the acute angle around the curvatures. The WSS on the inside curvature is higher than on the outside curvature. The ratio of the WSS in the inside curvature to WSS in the outside curvature is about in the range of 3 and 5. The WSS around the flow divider, firstly, declined, and then, slightly raised to high WSS values at the acute angle branch side of the divider, and giving rise to high WSS values at the obtuse angle branch side of the divider. However, the maximum value of the WSS around bifurcation decreased. Key Words: Pulsatile pressure flow, non-Newtonian, two-phase, blood flow, periodic body acceleration, hemodynamic parameters, Right Coronary Artery (RCA), Left Coronary Artery (LCA)