Effect of turbulent inlet conditions on the prediction of flow field and hemolysis in the FDA ideal medical device

作者：Peng Wu, Liudi Zhang, Qi Gao, Weifeng Dai · 发表于：Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science · 年份：2019 · DOI：10.1177/0954406219886334 · 被引用次数：6 · 研究领域：Mechanical Circulatory Support Devices、Blood donation and transfusion practices、Plasma and Flow Control in Aerodynamics

Hemolysis is one of the most important issues of blood contacting artificial organs. Computational fluid dynamics, in conjunction with hemolysis models, has been widely used to predict the flow field and hemolysis during the development phase of these devices. It is widely accepted that hemolysis is related to flow field parameters, such as stress and energy dissipation. It is known that inlet boundary conditions such as turbulent intensity have important effects on flow fields. Nonetheless, the influence of inlet turbulent intensity on hemolysis is not yet clear. This study investigates the influence of turbulent intensity on the prediction of flow field and hemolysis in the FDA benchmark nozzle model. Three configurations are investigated: first is the original nozzle model (with a gradual contraction, throat, and sudden expansion); the second is composed only of the throat and sudden expansion; the third one is similar with the second, but with a shorter throat. Four turbulent intensities are considered, ranging from 1% to 20%. For the first configuration, the influence of turbulent intensity on both flow field and hemolysis is very small and limited prior to the gradual contraction, while for the other two configurations, the influence is considerable. The jet breaks down sooner with increased turbulent intensity. Both turbulence dissipation rate and Reynolds stress increase in the throat with increased turbulent intensity, but decrease after the jet breaks down. The infl...