| 论文简介 |
To study the dynamics of red blood cells (RBCs) in confined shear flows is essential to understand the flow behavior of RBCs in capillaries and in microfluidics, especially when the length scale of flow is comparable to RBC size. However, previous studies are focused on RBC dynamics in unbounded shear flows, and only a limited number of cases concern RBC dynamics in confined shear flow by using two-dimensional (2D) vesicle model. Here, we developed a more native-mimicking three-dimensional (3D) model to investigate RBC dynamics in confined shear flows. The present model can reproduce experimental data of the deformation of healthy RBCs under stretching of optical tweezers. Using the validated model, we found RBCs in a 3D confined shear flow can exhibit breathing, swinging and tumbling motion. Particularly, breathing and swinging were observed in previous 3D simulations of unbounded shear flow, but in previous 2D simulations of confined shear flow only tumbling and tank-treading were observed. In confined shear flows, the deformation of RBCs is significantly enlarged by increasing the confinement (i.e., ratio of RBC size to channel size), thus breathing is preferable than tumbling. By only increasing confinement, the dynamical state of RBCs can transit from tumbling to breathing through an intermittent state (i.e., breathing with a weak tumbling). These results give new insights into the dynamics of RBCs suspended in confined shear flows, and can be helpful for further studying the dynamics of RBC suspensions in capillaries and in microfluidics. |
(创新港)
