@article { author = {Rafiei, Ashkan and Saidi, Maysam}, title = {Numerical Evaluation on Blood Rheological Behavior in a Realistic Model of Aneurysmal Coronary Artery}, journal = {AUT Journal of Mechanical Engineering}, volume = {6}, number = {4}, pages = {579-596}, year = {2022}, publisher = {Amirkabir University of Technology}, issn = {2588-2937}, eissn = {2588-2945}, doi = {10.22060/ajme.2022.20917.6025}, abstract = {The aim of this study is to evaluate the blood rheological behavior within a coronary artery aneurysm in detail. The three-dimensional model was reconstructed from computed tomography angiography images of a 43-year-old man with a coronary artery aneurysm on the bifurcation. First, the effects of blood dynamic viscosity on the hemodynamic characteristics in the aneurysmal coronary artery were studied. Then, a comparison between Newtonian and non-Newtonian viscosity models was carried out using four non-Newtonian blood models, namely the Carreau, Modified Casson, Cross, and Carreau-Yasuda models. The results have been presented in the form of velocity contours, streamlines, pressure drop variation, wall shear stress, and oscillatory shear index. The outcomes showed that a 20% change in the Newtonian blood viscosity leads to almost up to 12% alters in the aneurysm wall shear stress and nearly 15-18% changes in the value of the other sections. The decrement of the blood viscosity declines the aneurysm rupture risk by reducing blood pressure and wall shear stress. Additionally, among studied viscosity models, the Modified Casson model predicts the highest value of average wall shear stress in all parts except for the aneurysm, whereas, the highest value in the aneurysm is related to the Carreau model, close to 5.3% greater than the Modified Casson. Moreover, the average wall shear stress in the Newtonian state is the lowest in comparison with non-Newtonian models.}, keywords = {Coronary artery aneurysm,computational fluid dynamics,Non-Newtonian fluid,blood viscosity,wall shear stress}, url = {https://ajme.aut.ac.ir/article_4956.html}, eprint = {https://ajme.aut.ac.ir/article_4956_0cd7aa92603dbc33d733551edf7b3018.pdf} }