AN EFFICIENT RED BLOOD CELL MODEL IN THE FRAME OF IB-LBM AND ITS APPLICATION

Abstract

A two-dimensional red blood cell (RBC) membrane model based on elastic and Euler–Bernoulli beam theories is introduced in the frame of immersed boundary-lattice Boltzmann method (IB-LBM). The effect of the flexible membrane is handled by the immersed boundary method in which the stress exerted by the RBC on the ambient fluid is spread onto the collocated grid points near the boundary. The fluid dynamics is obtained by solving the discrete lattice Boltzmann equation. A "ghost shape", to which the RBC returns when restoring, is introduced by prescribing a bending force along the boundary. Numerical examples involving tumbling, tank-treading and RBC aggregation in shear flow and deformation and restoration in poiseuille flow are presented to verify the method and illustrate its efficiency. As an application of the present method, a ten-RBC colony being compressed through a stenotic microvessel is studied focusing the cell–cell interaction strength. Quantitative comparisons of the pressure and velocity on specified microvessel interfaces are made between each aggregation case. It reveals that the stronger aggregation may lead to more resistance against blood flow and result in higher pressure difference at the stenosis.