Kinetic modeling of blood cells in a turbulent environment and its effect on hemolysis

Abstract

Through careful physical modeling, this study provides insight into the effect of forces on hemolysis exerted on blood cells in the viscous subrange of the turbulence spectrum. We constructed a simplified coupling model of eddy currents with blood cells and analyzed it using a membrane tension quantification index directly related to hemolysis. It is found that the membrane tension resulting from blood cell interactions changes the overall ensemble force by an order of magnitude and more, and in some high-energy vortices, even dominates the ensemble force. This finding emphasizes that blood cannot simply be regarded as a dilute flow field in simulating the hemolysis process, but the real mechanical forces exerted on blood cells must be fully considered. Based on these findings, we propose an improved blood cell shear force model, which optimizes the classical Kolmogorov theoretical formulation in the viscous subrange, and by combining the model with the blood cell trajectory equation, we have successfully modified the force environment of blood cells, which makes the simulation results closer to the reality. Under two operating conditions of the FDA blood pump (2.5 L/min, 3500 rpm, 7.0 L/min, 3500 rpm), the turbulent intermittency inside the flow field reaches the maximum effect at multiple Reynolds numbers. The error of the relative hemolysis value calculated by the new model is significantly reduced compared with the original model. The error from the experiments reached less than 8% under multiple computational conditions, demonstrating an excellent prediction ability.