An investigation on the rheodynamics of human red blood cells using high performance computations

Abstract

Studies on the haemodynamics of human circulation are clinically and scientifically important. The flow of human blood is extremely complex due to the existence of the highly deformable red blood cells (RBCs), which are able to pass through capillaries smaller than their size. To investigate the effect of deformation and aggregation in blood flow, a computational technique has been developed by coupling the interaction between the fluid and the deformable solids. The flow of 49,512 RBCs at 45% concentration and under the influence of aggregating forces was examined to improve the existing knowledge on how to simulate and study the blood flow and its structural characteristics of blood at a large scale. The simulation was carried out with full parallelization of the coupled fluid-solid code using spatial decomposition and high performance supercomputers. The large scale feature of the simulation has enabled a macroscale verification and investigation of the overall characteristics of RBC aggregations to be carried out. The results are in excellent agreement with experimental studies and, more specifically, both the experimental and the simulation results show uniform RBC distributions under high shear rates (60-100/s) whereas large aggregations were observed under a lower shear rate of 10/s. The statistical analysis of the simulation data also shows that the shear rate has significant influence on both the flow velocity profiles and the frequency distribution of the RBC orientation angles. The flow under the low shear rate also tended to have bi-phasic velocity profile which is mainly due to the formation of large scale aggregation clusters.