The effect of turbulence model on predicting the development and progression of coronary artery atherosclerosis

A severe case of stenosis in coronary arteries results in turbulence in the blood flow which may lead to the formation or progression of atherosclerosis. This study investigated the turbulent blood flow in a coronary artery with rigid walls, as well as 80% single and double stenoses on blood flow. A finite element-based software package, ADINA 8.8, was employed to model the blood flow. The hemodynamic parameters of blood, such as the Oscillatory Shear Index (OSI) and the Mean Wall Shear Stress (Mean WSS) were obtained by both k-ε and k-ω turbulence models and then compared. According to the results, the negative pressure predicted by the k-ω turbulence model was several times greater than that by the k-ε turbulence model for both single and double stenoses. This, in turn, leads to the collapse of artery walls and irreparable injuries to the downstream extremity. Furthermore, the k-ω model predicted a larger reverse flow region in the post-stenotic region. In other words, the k-ω turbulence model predicts a larger part of the post-stenotic region to be prone to disease and the k-ε turbulence model predicted a higher rate of plaque growth. Moreover, the k-ω model predicted a much more intense reverse flow region than the k-ε model, which itself can lead to blood pressure disease.