Numerical simulation of motion and deformation of healthy and sick red blood cell through a constricted vessel using hybrid lattice Boltzmann-immersed boundary method

In the present article, hybrid lattice Boltzmann-immersed boundary method is utilized to simulate two-dimensional incompressible viscous flow involving flexible immersed red blood cell (RBC) in a microchannel. The main focus of the present research is to study motion and deformation of both healthy and sick RBCs in a vessel with different sizes of stenosis. The presented computational results consent reasonably well with the available data in the literature. Two different channels i.e. a simple and a constricted channel are investigated in the present manuscript. The results show that the RBC transfer and deform without any lift force and rotation induced when it is located on the symmetry axis of the microchannel. However, when the RBC is located off the symmetry axis, the pressure difference produced in the flow around the RBC would apply lift forces on them and expel them towards the center of the channel. The healthy RBC always shows more deformation related to the sick one along the channel. Another important result of the present research is that for the ratio of dD≤0.3$ \frac{{d}}{{D}} \le 0.3 $ a sick RBC cannot pass the stenosis, and it reasons serious difficulties for body. The present results have been compared with the available experimental and numerical results which show good agreements.